Calculators & Converters
Free online calculators and unit converters for finance, health, math, science, home improvement and everyday questions. Every calculator runs entirely in your browser — instant results, no signup, nothing sent to a server.
Business & Marketing
Meat Roasting Time Calculator
Roasting times and safe internal temperatures by weight and doneness.
Electricity Bill Estimator
Turn watts and hours into a daily, monthly and yearly cost.
Electricity Cost Calculator
Add every appliance, set your tariff, and see daily, monthly and yearly running costs.
Contribution Margin Calculator
Instantly find your CM per unit, CM ratio, break-even point and operating leverage.
Current Ratio Calculator
Instant liquidity analysis: current ratio, quick ratio, cash ratio and net working capital.
EBITDA Calculator
Calculate EBITDA, margins, EV/EBITDA, and key leverage ratios instantly.
Economic Order Quantity (EOQ) Calculator
Find the optimal order size that minimises total inventory cost.
Payback Period Calculator
Find how long until your investment breaks even — simple and discounted methods.
Quick Ratio Calculator (Acid-Test)
Instantly measure short-term liquidity — does your business have enough liquid assets to cover current debts?
Return on Assets (ROA) Calculator
Measure how efficiently a business turns its asset base into profit.
Return on Equity Calculator
Calculate ROE — basic, DuPont 3-factor and DuPont 5-factor decomposition.
Working Capital Calculator
Measure liquidity: current ratio, quick ratio, cash conversion cycle and more.
Debt-to-Equity Ratio Calculator
Compute D/E ratio, net leverage, debt ratio and interest coverage from a balance sheet.
Electric Field Calculator
Solve E = k·Q/r², V = k·Q/r, F = qE and Gauss's Law with full working shown.
Photoelectric Effect Calculator
Calculate KE, stopping voltage, threshold frequency and wavelength using Einstein's equation KE = hf − φ.
Burn Rate & Runway Calculator
Know exactly how long your cash will last — and what to do about it.
Customer Acquisition Cost (CAC) Calculator
Calculate blended CAC, LTV:CAC ratio and payback period by channel.
MRR Calculator
Calculate Monthly Recurring Revenue, ARR, LTV and forward projections.
A/B Test Significance Calculator
Know whether your experiment result is real — two-proportion z-test with p-value, confidence interval and power check.
ARR Calculator
Calculate Annual Recurring Revenue, NRR, GRR and MRR bridge in seconds.
Average Order Value Calculator
Calculate AOV, compare periods and find the AOV needed to hit a revenue target.
CAC Payback Period Calculator
Find out how many months it takes to recover your customer acquisition cost.
Churn Rate Calculator
Calculate customer churn, MRR churn, LTV, and cohort retention — all in your browser.
Click-Through Rate (CTR) Calculator
Instantly calculate CTR, CPC, CPM, conversion rate and ROAS from your campaign data.
Conversion Rate Calculator
Calculate CVR, ROAS, CPA and test A/B significance in one place.
Cost Per Acquisition (CPA) Calculator
Calculate CPA, LTV, ROAS, CTR, payback period and campaign ROI in one place.
CPC Calculator — Cost Per Click, CTR, ROAS & CPA
Work out your CPC, CTR, CPM, CPA, ROAS and campaign profit in one place.
CPM Calculator
Calculate CPM, total ad spend, or impressions — plus CTR, CPC, CPL and ROAS.
Customer Lifetime Value Calculator
Calculate LTV, LTV:CAC ratio and CAC payback period instantly.
Customer Retention Rate Calculator
Calculate CRR, churn rate, and LTV from your customer counts — single period, trend, or industry benchmark.
Email Open Rate Calculator
Calculate open rate, CTR, CTOR, bounce rate and A/B significance for any email campaign.
Engagement Rate Calculator
Calculate ER by reach, followers, impressions or views — with platform benchmarks.
Gross Merchandise Value (GMV) Calculator
Calculate total marketplace transaction volume, take-rate revenue and net revenue across periods.
LTV to CAC Ratio Calculator
Measure unit economics — how much a customer is worth vs. what it costs to acquire them.
Net Promoter Score (NPS) Calculator
Calculate your NPS instantly from group counts or raw 0–10 survey responses.
ROAS Calculator
Calculate Return on Ad Spend — instantly see ROAS, break-even, POAS and net profit.
Startup Runway Calculator
See exactly how many months of cash you have left — and when revenue covers burn.
Bounce Rate Calculator
Calculate your bounce rate, engagement rate and improvement projection — instantly.
Monthly Active Users (MAU) Calculator
Track MAU growth, churn, stickiness and 30-day retention across multiple periods.
Viral Coefficient Calculator
Calculate K-factor and model exponential growth wave by wave.
Tax & Wages
VAT & Sales Tax Calculator
Add or remove VAT, GST or sales tax for any country.
Take-Home Pay & Salary Tax Calculator
Net salary after income tax and social contributions — UK, US, Germany.
Georgia (GEL) Salary & Take-Home Pay Calculator
Net salary after Georgia's flat 20% income tax and 2% pension.
Bangladesh Income Tax Calculator (FY 2024-25, NBR)
আয়কর হিসাব করুন — calculate your Bangladesh income tax instantly.
Saudi Arabia & UAE VAT Calculator (GCC) — Arabic RTL Friendly
Add or extract VAT for Saudi Arabia, UAE, Bahrain and Oman — with Arabic RTL layout.
Austria USt Calculator (Umsatzsteuer) 2025
Add or extract Austria Umsatzsteuer at 20% — instant result in your browser.
Canada GST Calculator (Goods and Services Tax) 2025
Add or extract Canada Goods and Services Tax at 5% — instant result in your browser.
Czech Republic DPH Calculator (Daň z přidané hodnoty) 2025
Add or extract Czech Republic Daň z přidané hodnoty at 21% — instant result in your browser.
Denmark Merværdiafgift Calculator (Moms) 2025
Add or extract Denmark Moms at 25% — instant result in your browser.
Egypt VAT Calculator (Value Added Tax) 2025
Add or extract Egypt Value Added Tax at 14% — instant result in your browser.
Finland ALV Calculator (Arvonlisävero) 2025
Add or extract Finland Arvonlisävero at 25.5% — instant result in your browser.
Ghana VAT Calculator (Value Added Tax) 2025
Add or extract Ghana Value Added Tax at 15% — instant result in your browser.
Greece ΦΠΑ / FPA Calculator (Φόρος Προστιθέμενης Αξίας) 2025
Add or extract Greece Φόρος Προστιθέμενης Αξίας at 24% — instant result in your browser.
Hungary ÁFA Calculator (Általános Forgalmi Adó) 2025
Add or extract Hungary Általános Forgalmi Adó at 27% — instant result in your browser.
Portugal IVA Calculator (Imposto sobre o Valor Acrescentado) 2025
Add or extract Portugal Imposto sobre o Valor Acrescentado at 23% — instant result in your browser.
Romania TVA Calculator (Taxa pe Valoarea Adăugată) 2025
Add or extract Romania Taxa pe Valoarea Adăugată at 19% — instant result in your browser.
Turkey KDV Calculator (Katma Değer Vergisi) 2025
Add or extract Turkey Katma Değer Vergisi at 20% — instant result in your browser.
Bolivia Income Tax Calculator 2025 — 13% Flat Rate
Calculate your Bolivia take-home pay under the 13% flat income tax — monthly or annual, instant result in your browser.
Bosnia and Herzegovina Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Bosnia and Herzegovina take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Bulgaria Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Bulgaria take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Estonia Income Tax Calculator 2025 — 20% Flat Rate
Calculate your Estonia take-home pay under the 20% flat income tax — monthly or annual, instant result in your browser.
Hungary Income Tax Calculator 2025 — 15% Flat Rate
Calculate your Hungary take-home pay under the 15% flat income tax — monthly or annual, instant result in your browser.
Kazakhstan Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Kazakhstan take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Mongolia Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Mongolia take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
North Macedonia Income Tax Calculator 2025 — 10% Flat Rate
Calculate your North Macedonia take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Romania Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Romania take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Russia Income Tax Calculator 2025 — 13% Flat Rate
Calculate your Russia take-home pay under the 13% flat income tax — monthly or annual, instant result in your browser.
Turkmenistan Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Turkmenistan take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Vikram Samvat Converter
Convert between Gregorian (CE) and Vikram Samvat (VS) years.
GST Inclusive / Exclusive Calculator
Add or remove GST at any rate — see net, GST and gross.
Reverse Sales Tax Calculator
Strip VAT, GST or sales tax out of a tax-inclusive price.
Paycheck Budget Split
Split your pay into needs, wants and savings.
Paycheck Splitter
Split every paycheck across needs, wants and savings — 50/30/20 or your own rules.
GST Calculator
Add or remove GST and see the net, tax and gross amounts instantly.
Salary to Hourly Converter
Turn any annual salary into hourly, daily, weekly and monthly pay — or work it backwards.
US Sales Tax Calculator
Enter an amount and a state to get the sales tax and total — with a 50-state rate reference.
Overtime Pay Calculator
Turn a regular rate, base hours and one or more overtime multipliers into a full gross-pay breakdown.
Australia GST Calculator
Add or remove 10% GST instantly — with a full AUD breakdown.
Belgium VAT Calculator (TVA / BTW)
Add or remove Belgian VAT at 21%, 12%, 6% or 0% — instant net and gross breakdown.
Germany VAT Calculator (Mehrwertsteuer)
Add or remove German MwSt at 19%, 7%, or 0% — instant net/gross breakdown.
Ireland VAT Calculator
Add or remove Irish VAT instantly — 23%, 13.5%, 9% and 4.8% rates covered.
Italy VAT (IVA) Calculator
Add or remove Italian IVA at 22%, 10%, 5% or 4% — instant breakdown in euros.
New Zealand GST Calculator
Add or remove 15% NZ GST instantly — with a full breakdown.
Norway VAT (MVA) Calculator
Add or remove Norwegian merverdiavgift at 25%, 15%, and 12% in seconds.
Poland VAT Calculator
Add or remove Polish VAT (PTU) instantly — 23%, 8%, and 5% rates.
Singapore GST Calculator
Add or remove 9% GST in seconds — net, GST amount, and gross in one view.
Philippines VAT Calculator
Add or remove Philippine 12% EVAT — instant peso breakdown for any transaction.
UAE VAT Calculator
Add or remove UAE VAT at 5% or 0% — instant AED net/gross breakdown.
India GST Calculator — All Slabs: 5%, 12%, 18%, 28% + CGST/SGST Split
Add or extract GST at any slab rate with a full CGST/SGST/IGST breakdown.
Arizona Sales Tax Calculator 2025 — 5.6% State TPT Rate + Local
Add or remove Arizona sales tax with the real 5.6% state rate and editable local rate — instant browser calculation.
California Sales Tax Calculator
Add or reverse California sales tax in seconds — state 7.25% + your local rate.
Florida Sales Tax Calculator 2025 — 6% State Rate + County Surtax
Add or remove Florida sales tax instantly — state base rate preset, editable county surtax, full breakdown.
France VAT (TVA) Calculator
Add or remove French TVA at 20%, 10%, 5.5% or 2.1% — instant net/gross breakdown.
Illinois Sales Tax Calculator
Add or back out Illinois sales tax — state 6.25% plus your local rate.
Michigan Sales Tax Calculator 2025 — 6% Flat State Rate
Add or remove Michigan's flat 6% sales tax instantly — no local rate complications.
New York Sales Tax Calculator
Calculate NY sales tax instantly — add tax to a price or strip it from a total.
Netherlands VAT (BTW) Calculator
Add or remove Dutch BTW at 21%, 9% or 0% — instant net/gross breakdown.
Ohio Sales Tax Calculator
Instantly calculate Ohio sales tax — add tax to a price or back it out of a total.
Pennsylvania Sales Tax Calculator
Calculate PA sales tax — add it to a price or back it out from a total.
South Africa VAT Calculator
Add or remove 15% South African VAT instantly — net, VAT amount and gross in one click.
Spain VAT (IVA) Calculator
Add or remove Spanish IVA instantly — 21%, 10% and 4% rate bands covered.
Switzerland VAT (MWST) Calculator 2025 — 8.1%, 3.8%, 2.6%
Add or remove Swiss MWST at 8.1%, 3.8% or 2.6% — instant CHF breakdown in your browser.
Texas Sales Tax Calculator
Calculate Texas sales tax instantly — add tax to a price or back it out of a total.
Canada Sales Tax Calculator (GST/HST/PST) by Province 2025
Instantly calculate GST, HST, PST and QST for every Canadian province and territory.
Mexico VAT (IVA) Calculator — 16%, 8% Border Zone, 0%
Add or remove Mexican IVA at 16%, 8% border-zone, or 0% — full MXN breakdown instantly.
Saudi Arabia VAT Calculator
Add or remove 15% Saudi VAT instantly — net, VAT amount and gross in one click.
Missouri Sales Tax Calculator
Instantly calculate Missouri sales tax — add tax to a price or strip it from a total.
Massachusetts Sales Tax Calculator
Add or reverse Massachusetts sales tax instantly — state 6.25% + optional local meals rate.
Alabama Sales Tax Calculator 2025 — 4% State Rate + Local
Add or remove Alabama sales tax with the real 4% state rate and editable local rate — instant browser calculation.
Colorado Sales Tax Calculator 2025 — 2.9% State Rate + Local
Add or remove Colorado sales tax with the real 2.9% state rate and editable local rate — instant browser calculation.
Georgia Sales Tax Calculator 2025 — 4% State + Local Rate
Add or remove Georgia sales tax instantly — state 4% base plus editable local rate.
Indiana Sales Tax Calculator 2025 — 7% State Rate, No Local Tax
Add or remove Indiana sales tax with the real 7% state rate — instant browser calculation, no local tax complications.
Kenya VAT Calculator 2025 — 16% Standard & 8% Petroleum Rate
Add or remove Kenya VAT at the correct rate band — instant KSh breakdown in your browser.
New Jersey Sales Tax Calculator 2025 — 6.625% State Rate
Add or remove New Jersey sales tax instantly — state rate preset, editable local field, full breakdown.
North Carolina Sales Tax Calculator 2025 — 4.75% State Rate + Local
Add or remove NC sales tax instantly — state 4.75% base, editable county rate, full breakdown.
Nigeria VAT Calculator — 7.5% Value Added Tax (2025)
Add or remove Nigeria VAT at 7.5% — instant breakdown in your browser.
Sweden VAT (Moms) Calculator 2025 — 25%, 12%, 6%
Add or remove Swedish Moms instantly — all four rate bands, full SEK breakdown.
Washington Sales Tax Calculator
Add or reverse Washington sales tax — 6.5% state base rate + editable local rate.
Louisiana Sales Tax Calculator 2025 — 4.45% State Rate + Local
Add or remove Louisiana sales tax with the real 4.45% state rate and editable parish/city rate — instant browser calculation.
Maryland Sales Tax Calculator 2025 — 6% Flat State Rate
Add or remove Maryland sales tax instantly — 6% statewide, no local add-ons.
Minnesota Sales Tax Calculator
Add or reverse Minnesota sales tax instantly — state 6.875% + your local rate.
Tennessee Sales Tax Calculator 2025 — 7% State Rate + Local Rate
Add or remove Tennessee sales tax instantly — 7% state base preset, editable local rate, full breakdown.
Virginia Sales Tax Calculator 2025 — 4.3% State + Local Rate
Add or remove Virginia sales tax instantly — state 4.3% base plus editable local/regional rate.
South Carolina Sales Tax Calculator 2025 — 6% State Rate + Local
Add or remove SC sales tax instantly — state 6% base, editable county rate, full breakdown.
Wisconsin Sales Tax Calculator 2025 — 5% State Rate + Local
Add or remove Wisconsin sales tax using the real 5% state rate and an editable county/city rate — instant browser calculation.
Alabama Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Alabama (federal) minimum wage, with overtime.
Arizona Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Arizona's $14.70/hr minimum — plus overtime.
Arkansas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Arkansas's $11.00/hr minimum wage — with overtime.
California Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at California's $16.50/hr minimum — with overtime.
Florida Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Florida's $13/hr minimum — with overtime.
New York Minimum Wage Calculator
Compute gross pay at New York's $16.50/hr minimum wage — weekly, monthly, and annual.
Oregon Minimum Wage Calculator
Compute gross pay weekly, monthly and annually for all three Oregon wage tiers (July 2025) — with overtime.
Alaska Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Alaska's $11.91/hr rate — with overtime.
Colorado Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Colorado's $14.81/hr minimum wage, with overtime.
Connecticut Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at CT's $16.35/hr minimum wage — with overtime.
Hawaii Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Hawaii's $16/hr minimum — with overtime.
Illinois Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Illinois's $14/hr minimum — with overtime.
Maryland Minimum Wage Calculator
Compute gross pay at Maryland's $15.00/hr minimum — weekly, monthly, annual, with overtime.
Massachusetts Minimum Wage Calculator
Compute gross pay at the $15.00/hr MA minimum wage — weekly, monthly, annual, with overtime.
Michigan Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Michigan's $10.56/hr minimum wage, with overtime.
Missouri Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Missouri minimum wage, with overtime.
Montana Minimum Wage Calculator
Calculate gross pay at Montana's $10.55/hr minimum wage — weekly, monthly and annual.
New Jersey Minimum Wage Calculator
Instantly compute gross weekly, monthly, and annual pay at New Jersey's $15.49/hr minimum wage — with overtime.
New Mexico Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at the New Mexico minimum wage — with overtime.
Nebraska Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Nebraska minimum wage of $13.50/hr, with overtime.
Ohio Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Ohio's $10.70/hr minimum wage, with overtime.
Maine Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Maine's $14.65/hr rate — with overtime.
Minnesota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Minnesota's $11.13/hr minimum wage, with overtime.
Nevada Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Nevada's $12/hr minimum — with overtime.
Alabama Property Tax Calculator
Estimate your Alabama annual and monthly property tax from your home value and the state average effective rate.
Arizona Property Tax Calculator 2024 — Estimate Your Annual and Monthly Bill
Enter your home value and get an instant Arizona property-tax estimate using the real 0.51% statewide average effective rate.
California Property Tax Calculator
Estimate your annual and monthly California property tax using the real statewide average effective rate.
Colorado Property Tax Calculator
Estimate your annual and monthly Colorado property tax from your home value.
Florida Property Tax Calculator
Estimate your annual and monthly Florida property tax from home value and effective rate.
Georgia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Georgia (federal) minimum wage — overtime included.
Georgia Property Tax Calculator
Estimate your annual and monthly property tax bill for any Georgia county.
Iowa Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Iowa minimum wage, with overtime.
Kentucky Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Kentucky (federal) minimum wage, with overtime.
Pennsylvania Minimum Wage Calculator
Compute PA gross weekly, monthly and annual pay with overtime at the current state minimum wage.
Texas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Texas minimum wage with overtime.
Louisiana Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Louisiana (federal) minimum wage, with overtime.
Connecticut Property Tax Calculator
Estimate your annual and monthly CT property tax — with county breakdowns.
Idaho Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Idaho minimum wage, with overtime.
Illinois Property Tax Calculator
Estimate your Illinois annual and monthly property tax from your home value and the state average effective rate.
Indiana Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Indiana minimum wage, with overtime.
Kansas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Kansas minimum wage, with overtime.
Massachusetts Property Tax Calculator
Estimate your Massachusetts annual and monthly property tax from your home value and the state average effective rate.
Michigan Property Tax Calculator
Estimate your Michigan annual and monthly property tax from your home value and the state average effective rate.
Mississippi Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Mississippi (federal) minimum wage, with overtime.
Missouri Property Tax Calculator
Estimate your Missouri annual and monthly property tax from your home value and the state average effective rate.
Nevada Property Tax Calculator
Estimate your Nevada annual and monthly property tax from your home value and the state average effective rate.
New Hampshire Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the New Hampshire (federal) minimum wage, with overtime.
New York Property Tax Calculator
Estimate your New York annual and monthly property tax from your home value and the state average effective rate.
North Carolina Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the North Carolina minimum wage, with overtime.
North Dakota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the North Dakota (federal) minimum wage, with overtime.
Ohio Property Tax Calculator
Estimate your Ohio annual and monthly property tax from your home value and the state average effective rate.
Oklahoma Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Oklahoma (federal) minimum wage, with overtime.
Oregon Property Tax Calculator
Estimate your Oregon annual and monthly property tax from your home value and the state average effective rate.
South Carolina Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the South Carolina (federal) minimum wage, with overtime.
South Dakota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the South Dakota minimum wage, with overtime.
Tennessee Property Tax Calculator
Estimate your Tennessee annual and monthly property tax from your home value and the state average effective rate.
Texas Property Tax Calculator
Estimate your Texas annual and monthly property tax from your home value and the state average effective rate.
Wisconsin Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Wisconsin minimum wage, with overtime.
Wyoming Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Wyoming minimum wage, with overtime.
Rhode Island Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at RI's $16.00/hr minimum wage — with overtime.
Minnesota Property Tax Calculator
Estimate your Minnesota annual and monthly property tax from your home value and the state average effective rate.
New Jersey Property Tax Calculator
Estimate your NJ annual and monthly property tax from your home value and the state average effective rate.
North Carolina Property Tax Calculator
Estimate your North Carolina annual and monthly property tax from your home value and the state average effective rate.
Pennsylvania Property Tax Calculator
Estimate your Pennsylvania annual and monthly property tax from your home value and the state average effective rate.
Tennessee Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Tennessee (federal) minimum wage, with overtime.
Utah Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Utah minimum wage, with overtime.
Virginia Property Tax Calculator
Estimate your Virginia annual and monthly property tax from your home value and the locality effective rate.
Washington State Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Washington's $16.66/hr minimum wage — with overtime.
Wisconsin Property Tax Calculator
Estimate your Wisconsin annual and monthly property tax from your home value and the state average effective rate.
Indiana Property Tax Calculator
Estimate your Indiana annual and monthly property tax from your home value and the state average effective rate.
Vermont Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Vermont minimum wage, with overtime at 1.5x.
Washington Property Tax Calculator
Estimate your Washington annual and monthly property tax from your home value and the state average effective rate.
Virginia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Virginia's $12.41/hr minimum wage, with overtime.
West Virginia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the West Virginia minimum wage of $8.75/hr, with overtime.
Kinematics Calculator (SUVAT + Projectile)
Solve any SUVAT equation or projectile problem — pick the unknown and get full working.
Delaware Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Delaware's $15.00/hr minimum wage with overtime.
Activation Energy Calculator
Arrhenius equation, two-point Eₐ, first-order half-life and Eyring–Polanyi in one tool.
Boiling Point Elevation Calculator
Calculate ΔTb = i · Kb · m — solve for elevation, Kb, molality or Van't Hoff factor.
Elevation Grade Calculator
Convert between slope grade %, angle, rise, run and slope distance instantly.
Medical & Clinical
Blood Alcohol Content (BAC) Calculator
Estimate your BAC with the Widmark formula — never use it to decide to drive.
Metabolic Age Calculator
Estimate your metabolic age from your BMR.
Anion Gap Calculator
Instantly compute anion gap, albumin-corrected AG, delta ratio and osmolar gap.
APGAR Score Calculator
Assess a newborn's health at birth with the standard five-criterion APGAR scale.
Body Surface Area (BSA) Calculator
Calculate BSA using Mosteller, DuBois, Haycock and three more formulae — instantly in your browser.
Cat Years Calculator
Find out how old your cat is in human years — with life-stage guidance.
Corrected Calcium Calculator
Adjust serum calcium for low or high albumin using the Payne formula.
Creatinine Clearance Calculator (Cockcroft-Gault)
Estimate kidney function for drug dosing using the Cockcroft-Gault equation.
eGFR Calculator (CKD-EPI 2021)
Estimate kidney function from serum creatinine using the latest race-free equation.
Gestational Age Calculator
Find out exactly how far along you are — in weeks and days.
eGFR Calculator (CKD-EPI 2021)
Estimate kidney function using the latest race-free CKD-EPI 2021 equation.
MAP Calculator (Mean Arterial Pressure)
Instantly compute Mean Arterial Pressure from systolic and diastolic readings.
Mean Arterial Pressure (MAP) Calculator
Instantly compute MAP from systolic and diastolic blood pressure readings.
Pet Age Calculator
Convert your pet's age to a human-equivalent age using real veterinary science.
QTc Interval Calculator
Correct the QT interval for heart rate using Bazett, Fridericia, Framingham and Hodges formulas.
Dog Years Calculator
Convert your dog's age to human years with size-aware milestones and life-stage analysis.
Caffeine Half-Life Calculator
See exactly how much caffeine is still in your system and when you can safely sleep.
Glycemic Load Calculator
Calculate the glycemic load of any meal from a database of 60+ foods.
Sugar Intake Calculator
Track your daily sugar consumption against WHO, AHA and NHS limits.
Fiber Intake Calculator
Find your daily fiber target and track it food by food.
Sodium Intake Calculator
Track your daily sodium and salt intake against WHO, AHA and NHS limits.
Standard Drink Calculator
Convert any drink into standard units for US, UK, Australia and Canada.
Health & Fitness
BMI / BMR / TDEE Calculator
Body mass index, basal metabolic rate and daily calorie needs in one tool.
Pregnancy Due Date Calculator
Estimated due date, gestational age and trimester from your last period.
BMR Calculator
Your Basal Metabolic Rate with the Mifflin-St Jeor equation.
TDEE Calculator
Total Daily Energy Expenditure from BMR and activity level.
Body Fat Calculator
Estimate body fat percentage with the US Navy method.
Ideal Weight Calculator
Ideal body weight from four classic formulas.
Lean Body Mass Calculator
Lean mass and fat mass from the Boer formula.
Calorie Deficit Calculator
Find your daily calorie target for steady, safe weight loss.
Macro Calculator
Split your daily calories into protein, carbs and fat in grams.
Water Intake Calculator
Estimate how much water to drink each day for your body and activity.
Running Pace Calculator
Work out pace, finish time or distance for any run.
One Rep Max Calculator
Estimate your 1RM and training weights from a set you can do.
Sleep Cycle Calculator
Find the best bedtime or wake-up time around 90-minute cycles.
Joules to Calories Converter
Convert J to cal instantly — 1 cal = 4.184 J. Free, browser-only tool.
Pregnancy Week Tracker
See how many weeks pregnant you are, your trimester and your due date.
Calorie Burn by Activity Calculator
Estimate calories burned for any activity using MET values.
BMI Prime Calculator
Express your BMI as a ratio to the healthy-weight ceiling of 25.
Waist-to-Height Ratio Calculator
Check if your waist is less than half your height — a simple health screen.
VO2 Max Calculator
Estimate your VO2 max from resting HR, a Cooper run or a Rockport walk.
Waist-to-Hip Ratio Calculator
Divide waist by hip and see your WHO health-risk band.
Protein Intake Calculator
How much protein per day for maintenance, muscle gain or fat loss.
Max Heart Rate Calculator
Your maximum heart rate plus five training zones, with Karvonen support.
Running Pace Converter
Convert between min/km, min/mile, km/h and mph instantly.
Pregnancy Weight Gain Calculator
Check your pregnancy weight gain against IOM guidelines by week.
Calories In vs Out Calculator
See your daily calorie balance and projected weight change.
Joules to Food Calories Converter
Convert joules to nutrition-label Calories (kcal) and back.
Calories to Joules Converter
Convert small (gram) calories to joules and back, exactly.
Target Heart Rate Zone Calculator
Training zones by Karvonen or percentage of max HR.
Calories Per Meal Planner
Split your daily calorie target across meals.
Steps to Calories Calculator
Convert your step count into calories burned.
Pregnancy Trimester Calculator
Find your trimesters, due date and gestational age.
BMI-for-Age Percentile Calculator
Child & teen BMI percentile using CDC growth charts.
Marathon Time Predictor
Predict your marathon finish from a recent race using the Riegel formula.
VDOT Running Calculator
Find your VDOT fitness score from any race time (Daniels–Gilbert model).
Swim Pace Calculator
Work out your pace per 100 m or 100 yd and average swim speed.
Calories to Kilojoules Converter
Convert food calories (kcal) to kilojoules, both directions.
Kilojoules to Calories Converter
Convert kilojoules to food calories (kcal), both directions.
Heart Rate Recovery Calculator
How fast your pulse drops after exercise.
Pace Per Kilometer Calculator
Turn distance and time into min/km, min/mile and km/h.
Daily Calorie Cycling Calculator
Split your weekly calories into high and low days.
Hydration Reminder Calculator
Your daily water target and a drink-every-X-minutes schedule.
Workout Program Builder
Build a weekly training split, track sets and reps, and export a printable PDF.
Macro Meal Planner
Plan a day of meals, hit your protein, carb and fat targets, export the plan.
Workout Log
Track sets, reps and weight per session — with history and personal-best highlights.
BMR & TDEE Calculator
Find your BMR, daily calorie burn and goal calorie targets in seconds.
Calorie & Macro Daily Tracker
Log foods against calorie and macro targets with live progress rings.
Body Fat Calculator (US Navy Method)
Estimate body fat % from a tape measure using the US Navy formula.
Sleep Cycle Calculator Pro
Bedtime, wake-up and nap times tuned to your own 90-minute cycles.
Heart Rate Zone Calculator
Turn your age and resting pulse into five training zones with exact BPM ranges.
One Rep Max Calculator (Pro)
Estimate your 1RM from seven formulas, with a full training-percentage table in kg and lb.
Water Intake Calculator (Advanced)
Personalised daily water target from weight, age, activity and climate.
BMI Calculator with Healthy Weight Range
Body mass index, your category, and the healthy weight range for your height.
Running Pace Calculator Pro: Pace, Time, Distance + Splits
Enter any two of pace, time and distance — get the third, plus splits and race predictions.
Sourdough Hydration & Baker's Percentage Calculator
Find your dough hydration and every baker's % in one click.
Pace Per Mile Calculator
Find your pace, finish time or distance — in minutes per mile.
Rowing Split Calculator
Convert your split to watts, calories and total time — or find the split you need to hit a goal time.
Steps to Miles Calculator
Convert any step count to miles and kilometres instantly.
Calories Burned Cycling Calculator
Find out exactly how many calories you burn on every ride.
Calories Burned Swimming Calculator
Find out exactly how many calories you burn for every stroke and session.
FFMI Calculator
Calculate your Fat-Free Mass Index and see how your muscularity compares.
Heart Rate Reserve Calculator
Find your true Karvonen training zones using the HRR method.
Marathon Pace Predictor
Goal time, training zones, negative splits and 5-km split cards — all from one number.
Plate Loading Calculator
Instantly know which plates to load on each side of the bar — kg and lb.
Running Cadence Calculator
Find your ideal steps per minute from speed and stride length.
Steps to Calories Calculator
Convert any step count to calories burned — with distance, pace, fat burned, and daily projections.
Wilks Calculator
Compare your powerlifting total across any bodyweight class.
Calories Burned Running Calculator
Find out exactly how many calories your run burns — by speed, weight and distance or time.
DPI / Dots Calculator
Calculate PPI for screens and DPI for print — find the right resolution in seconds.
Beep Test Calculator
Find your VO2 max and fitness rating from your 20m shuttle run level and shuttle.
Brzycki 1RM Calculator
Estimate your one-rep max from any rep-weight set using the Brzycki formula.
Cooper Test Calculator
Estimate VO2max from your 12-minute run — with age and sex fitness norms.
Epley 1RM Calculator
Estimate your one-rep max from any submaximal lift in seconds.
Treadmill Pace Converter
Convert treadmill speed to running pace, finish times and calorie burn instantly.
Calorie Cycling Calculator
Plan high, medium, low and rest-day calories around your training week.
RPE Load Calculator
Translate Rate of Perceived Exertion to exact training loads using the Tuchscherer RTS chart.
Waist-to-Height Ratio Calculator
Check your central obesity risk with the simple keep-your-waist-to-half-your-height rule.
Waist-to-Hip Ratio Calculator
Calculate your WHR, see your WHO risk band, and solve for the waist size you need.
Wendler 5/3/1 Calculator
Generate your full 4-week 5/3/1 cycle — sets, weights, AMRAP targets and progression.
Grade Adjusted Pace Calculator (GAP)
Find your flat-equivalent running pace on any hill using the Minetti metabolic model.
Reverse Diet Calculator
Ramp calories back to maintenance with minimal fat gain.
Running Economy Calculator
Calculate your oxygen cost per km, energy cost (Cr) and running efficiency from a sub-maximal VO2 test.
TDEE Calculator — Katch–McArdle & Cunningham
The most accurate lean-mass TDEE: Katch–McArdle + Cunningham, with solve-for-body-fat mode.
Pregnancy Due Date Calculator
Find your estimated due date using LMP, conception, IVF transfer, or ultrasound dating.
Ovulation Calculator
Find your fertile window and estimated ovulation date for the next 1–6 cycles.
Pregnancy Week Calculator
Find out exactly which week of pregnancy you are in and see what comes next.
Running Pace to Speed Converter (Tempo to mph / km/h)
Convert any running pace to mph, km/h and m/s — plus instant race finish times.
Army Body Fat Calculator
Estimate body fat with the official U.S. Army AR 600-9 circumference formula and check your Army standard.
Fat-Burning Zone Calculator
Find the exact heart-rate range where your body burns the most fat per minute.
Hydration During Exercise Calculator
Know exactly how much to drink before, during and after your workout.
Protein Per Meal Calculator
Find out exactly how much protein to eat at each meal for your body weight and goal.
Heart Rate Zone Calculator
Find your 5 training zones using Karvonen or % Max HR.
Target Heart Rate Calculator
Find your ideal training heart-rate zone for any fitness goal.
VO2max From Race Time Calculator
Derive your VDOT and five training pace zones from any recent race result.
Calories in Recipe Calculator
Total calories, macros and per-serving breakdown for any home-cooked dish.
Chemistry
Miles per Hour to Kilometres per Hour Converter
Convert mph to km/h instantly — 1 mph = 1.609344 km/h. Free, browser-only tool.
Miles per Hour to Knots Converter
Convert mph to kn instantly — 1 mph = 0.868976 kn. Free, browser-only tool.
Percent Yield Calculator
Percent yield from actual and theoretical yield — or solve either.
Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, moles or temperature — with units and steps.
Molarity Calculator
Solve for molarity, moles, mass or volume — with grams to moles built in.
pH Calculator
Convert between pH, pOH, [H⁺] and [OH⁻], and get pH from strong acid or base concentration.
Dilution Calculator (C1V1 = C2V2)
Solve the dilution equation for any concentration or volume, with units.
Molar Mass Calculator
Molar mass of any chemical formula, with per-element breakdown.
Cocktail Dilution Calculator
Know exactly how much ice water enters your drink — and where your ABV lands.
Titration Calculator
Find analyte concentration, titrant volume or equivalence point from any three knowns.
Ideal Gas Law Calculator (PV = nRT)
Solve for pressure, volume, moles or temperature — with full unit conversion.
Combined Gas Law Calculator
Solve P₁V₁/T₁ = P₂V₂/T₂ — plus Boyle, Charles, Gay-Lussac and the Ideal Gas Law.
Empirical Formula Calculator
Find the empirical and molecular formula from mass percentages or masses.
Enthalpy Calculator
Hess's Law, Gibbs ΔG, bond enthalpies, Kirchhoff, calorimetry — all in one tool.
Entropy & Gibbs Free Energy Calculator
Calculate ΔS, ΔG, Boltzmann entropy and more — six thermodynamic laws in one tool.
Equilibrium Constant Calculator
Kc, ICE tables, van't Hoff and Q vs Kc — all in one tool.
Gibbs Free Energy Calculator
Calculate ΔG, ΔH, ΔS, equilibrium constants and Nernst cell potentials instantly.
Molality Calculator
Calculate molality, solute mass, solvent mass, or molar mass — with full working shown.
pH and pOH Calculator
Convert between pH, pOH, and ion concentrations — with Henderson–Hasselbalch, buffer capacity, and dilution.
PPM Calculator
Convert ppm to molarity, run Beer-Lambert, dilute to a target concentration — all in one place.
Rate of Reaction Calculator
Arrhenius, rate laws, half-lives, activation energy — six chemistry modes in one tool.
Stoichiometry Calculator
Molar mass, limiting reagent, percent yield, molarity and ideal gas law — all in one place.
Atom Economy Calculator
Atom economy, E-factor, PMI, RME and mass balance — green chemistry metrics in one tool.
Beer-Lambert Law Calculator
Solve for absorbance, concentration, molar absorptivity, or path length instantly.
Boyle's Law Calculator
Solve P₁V₁ = P₂V₂ instantly — find any missing pressure or volume.
Charles's Law Calculator
Solve V1/T1 = V2/T2 instantly — find any gas volume or temperature at constant pressure.
Dalton's Law of Partial Pressures Calculator
Compute total pressure, partial pressures and mole fractions for any gas mixture.
Freezing-Point Depression Calculator
Calculate ΔTf, molality, Kf, or the van t Hoff factor — with full step-by-step working.
Gay-Lussac's Law Calculator
Solve P1/T1 = P2/T2 instantly — pressure, temperature, or both.
Graham's Law of Effusion Calculator
Compare gas effusion rates using r₁/r₂ = √(M₂/M₁). Solve for rate ratio, individual rate, or unknown molar mass.
Henderson-Hasselbalch Calculator
Solve pH, pKa, [A⁻] or [HA] with full step-by-step working.
Limiting Reagent Calculator
Find the limiting reagent, theoretical yield, excess amounts and percent yield instantly.
Mole Fraction Calculator
Find mole fractions, mole percentages and partial pressures for any gas or liquid mixture.
Normality Calculator
Calculate normality, equivalent weight, molarity conversions, dilutions and titration endpoints.
Osmotic Pressure Calculator (van 't Hoff: π = iMRT)
Solve for osmotic pressure, concentration, temperature or the van 't Hoff factor — with full unit support.
Theoretical Yield Calculator
Find theoretical yield, percent yield, or actual yield — with full stoichiometric working.
Nernst Equation Calculator
Calculate cell potential, standard E°, electrons transferred, reaction quotient or temperature — with full step-by-step working.
Percent Composition Calculator
Find the mass percent of every element in any chemical formula instantly.
Scoville Dilution Calculator
Calculate how much diluent to add to hit your target heat level.
Physics
Momentum Calculator
Momentum p = m × v and impulse J = F × t, instantly.
Gravitational Force Calculator
Newton's law of gravitation: F = G·m₁·m₂ / r².
Newtons to Pounds-force Converter
Convert newtons to pounds-force instantly — 1 lbf = 4.4482216 N. Free, browser-only.
Escape Velocity Calculator
Work out the speed needed to escape any body's gravity.
Orbital Period Calculator
Compute how long one orbit takes with Kepler's third law.
Celsius to Newton Scale Converter
Convert °C to the historic Newton temperature scale, both ways.
Kinetic Energy Calculator
Solve KE = ½ m v² for energy, mass, or velocity — with full working shown.
Projectile Motion Calculator
Launch speed and angle to range, max height, flight time — with trajectory chart.
Power-to-Weight Ratio Calculator
Compare two vehicles' power-to-weight ratios in W/kg, kW/t and hp/t.
Doppler Shift Calculator
Calculate observed frequency, redshift and wavelength change for sound or light.
Lens Equation Calculator
Solve the thin lens equation for f, do or di — plus magnification, optical power and a live ray diagram.
Pressure at Depth Calculator
Calculate hydrostatic pressure at any depth — gauge and absolute, any fluid.
Reynolds Number Calculator
Predict laminar, transitional or turbulent flow — solve for Re, velocity, length or viscosity.
Terminal Velocity Calculator
Calculate the terminal velocity of any falling object using real aerodynamics.
Buoyancy Calculator
Compute buoyant force, fluid density, or submerged volume using Archimedes' principle.
Gas Density Calculator
Calculate gas density from pressure, temperature and molar mass — or solve for P or T.
Pendulum Period Calculator
Calculate period, length or gravity for a simple pendulum using T = 2π√(L/g).
Snell's Law Calculator
Compute refracted angle, incident angle, or refractive index — with critical-angle and Fresnel reflectance.
Specific Heat Calculator
Calculate heat energy, mass, specific heat capacity or temperature change using Q = m·c·ΔT.
Spring Constant Calculator
Hooke's Law — solve for k, force, or displacement with elastic PE and natural frequency.
Thermal Expansion Calculator
Calculate linear, area and volumetric expansion for 30 materials using ΔL = α · L₀ · ΔT
Angular Velocity Calculator
Calculate angular velocity, centripetal acceleration, tangential speed and more — with unit conversions.
Free Fall Calculator
Solve distance, time, velocity or g for any free-fall problem — Earth, Moon, Mars and beyond.
Friction Calculator
Compute friction forces, normal forces, slip angles and incline acceleration — with full working shown.
Power Physics Calculator
Solve P = W/t, P = Fv, P = τω, P = VI, P = I²R, hydraulic, rotational KE and more — with full working shown.
Banking Angle Calculator
Find the ideal banking angle, speed, or curve radius for any banked turn.
Coulomb's Law Calculator
Calculate electrostatic force between two point charges — solve for F, q₁, q₂, or r.
de Broglie Wavelength Calculator
Calculate the quantum wavelength of any moving particle — electrons, protons, neutrons, or custom masses.
Frequency and Period Calculator
Instantly convert between frequency f, period T, and angular frequency omega — with unit-aware results across Hz to THz.
Gravitational Force Calculator
Newton's universal gravitation: F = G * m1 * m2 / r2. Solve for any variable.
Impulse Calculator
Solve J = F·Δt or J = m·v_f − m·v_i with step-by-step working.
Kinetic Friction Calculator
Calculate friction force, stopping distance, incline dynamics and work done by friction.
Moment of Inertia Calculator
Compute I for 11 shapes, solve rotational KE and angular momentum — with the parallel axis theorem built in.
Newton's Second Law Calculator
F = ma — solve for force, mass, acceleration plus impulse, work, friction, circular motion, and inclined planes.
Orbital Velocity Calculator
Find the speed needed for a circular orbit around any body — with escape velocity, period and geostationary orbit.
Torque Physics Calculator
Solve torque, angular acceleration, rotational power, work, and lever balance — with full working shown.
Work & Energy Calculator
Solve work, KE, PE, power, momentum, impulse, collisions and centripetal force — with full working shown.
Centripetal Force Calculator
Solve F = m·v²/r instantly — force, mass, velocity, or radius.
Gravitational Potential Energy Calculator
Calculate PE = mgh instantly — solve for energy, mass, height, or g.
Hooke's Law Calculator
Solve F=kx, elastic PE, series/parallel springs and SHM oscillation — with full working.
Projectile Range Calculator
R = v₀²·sin(2θ)/g — range, height, flight time, impact speed.
Wave Speed Calculator
v = f × λ — solve for wave speed, frequency, wavelength, or period.
Electronics
Resistor Color Code Calculator
Decode 4-band resistor colour bands to ohms.
Decibel (dB) Calculator
Convert a power or amplitude ratio to decibels.
Ohm's Law Calculator
Enter any two of V, I, R or P — get the other two with the formula wheel.
Resistor Color Code Calculator
Decode 4, 5 and 6-band resistors — or work backwards from a value to the colours.
Capacitor Code Calculator
3-digit EIA code to capacitance — and back. With tolerance band and voltage rating.
LED Resistor Calculator
Series resistor, nearest E12/E24 value and power rating — instantly.
Voltage Divider Calculator
Solve for Vout, Vin, R1 or R2 — with current, power and full working.
Battery Life Calculator
Capacity, load and efficiency → exact runtime hours, minutes and a discharge curve.
Wire Gauge (AWG) Calculator
AWG to diameter, ampacity with derating, and voltage drop for any run length.
555 Timer Calculator
Astable frequency, duty cycle and monostable pulse width — with full working.
LC Resonant Frequency Calculator
Find the resonant frequency, inductance, or capacitance of any LC tank circuit instantly.
Op-Amp Gain Calculator
Instantly calculate voltage gain, bandwidth and resistor values for any op-amp configuration.
PC Power Supply Calculator
Find the right PSU wattage for your build — CPU, GPU, storage and all.
Voltage Drop Calculator
Calculate voltage drop for any cable run — or find the minimum wire size for a target drop limit.
Antenna Length Calculator
Calculate the exact physical length for any antenna type from frequency — or find the resonant frequency from a known length.
Battery Runtime Calculator
Peukert-corrected runtime, required capacity, and max load for any battery pack.
Capacitor Charge Calculator
Calculate charge, voltage, capacitance, energy stored and dynamic charge/discharge voltage in an RC circuit.
Capacitor Parallel & Series Calculator
Instantly find the total capacitance of any combination of capacitors in parallel or series.
Decibel Distance Calculator
How loud is a sound at a different distance? Instant inverse-square-law answer.
Generator Sizing Calculator
Calculate the exact kVA rating you need — with motor surge, altitude and temperature derating.
RC Time Constant Calculator
Calculate τ = R × C, cutoff frequency, and capacitor voltage at any time.
Resistor Parallel Calculator
Equivalent resistance, conductance breakdown and solve-for-missing-R — all in one tool.
Transformer Turns Ratio Calculator
Compute secondary voltage, current, reflected impedance and winding counts for any transformer.
UPS Runtime Calculator
How long will your UPS last? Peukert-corrected battery runtime with real efficiency losses.
Resistor Series Calculator
Total resistance, current, voltage drops and power for any series resistor network.
Solar Battery Bank Calculator
Size a solar battery bank with the correct Ah formula — autonomy, DoD, efficiency, cell config.
Dipole Antenna Calculator
Instantly calculate half-wave dipole, quarter-wave monopole, and full-wave loop lengths for any frequency.
Capacitance Calculator
Parallel-plate, charge-voltage, energy stored, RC time constant, series and parallel combinations — all in one tool.
Inductance Calculator
Calculate inductance, reactance, energy, RL time constant and series/parallel combinations.
Resistivity Calculator
Calculate wire resistance, resistivity, length or cross-sectional area — with temperature correction.
Magnetic Force Calculator
Calculate Lorentz force on a charge, on a wire, or between two parallel wires — solve for any variable.
Decibel to Watt Calculator
Convert dB levels to watts (and watts to dB) with full working shown.
ADC Resolution Calculator
Compute LSB voltage, SNR, ENOB, quantisation noise and dynamic range for any ADC.
Amps to Watts Calculator
Convert amps to watts (or watts to amps) for DC, AC single-phase and AC three-phase circuits.
Capacitor Energy Calculator
Calculate the energy stored in a capacitor — plus series/parallel networks and RC discharge power.
Frequency to RPM Calculator
Convert Hz, kHz, rad/s and RPS to RPM — and back — instantly.
kVA to kW Calculator
Convert apparent power to real power instantly — single-phase and three-phase.
kW to kVA Calculator
Convert real power (kW) to apparent power (kVA) using power factor.
Power Dissipation Calculator
Calculate real, apparent and reactive power for DC circuits, AC single-phase and three-phase systems, plus junction temperature from thermal resistance.
Three-Phase Power Calculator
Calculate kW, kVA, kVAR, current and voltage for balanced three-phase AC systems.
Voltage Divider Output Calculator
Compute loaded and unloaded Vout, loading error, power, and nearest E-series resistor.
Watts to Amps Calculator
Convert watts to amps for DC, single-phase AC, and three-phase AC circuits.
Wire Resistance Calculator
Calculate conductor resistance, voltage drop and power loss for any material, length and cross-section.
Conduit Fill Calculator
Check NEC conduit fill compliance — pick a conduit, add wires, get the fill percentage instantly.
Motor FLA Calculator
Calculate full load amperes for single-phase and three-phase AC motors.
PWM Duty Cycle Calculator
Instantly compute duty cycle, frequency, t-on, t-off, period, average voltage, RMS voltage, and power for any PWM signal.
Automotive
FIRE Retirement Calculator
Find your FIRE number and how long until you reach it.
Horsepower to Watts Converter
Convert mechanical horsepower to watts and back, instantly.
Retirement & FIRE Planner
Project your portfolio to retirement, find your FIRE number, and see if it lasts.
Retirement Countdown
Live countdown to the day you reach your target retirement age.
RC Gear Ratio Calculator
Calculate pinion, spur and top speed for your RC car build.
Ackermann Angle Calculator
Calculate ideal inner and outer steer angles, turning radius and Ackermann percentage for any vehicle geometry.
Air-Fuel Ratio Calculator
Calculate AFR, lambda, and equivalence ratio for any fuel — gasoline, diesel, ethanol, methanol, hydrogen and more.
Brake Horsepower Calculator
Calculate BHP from torque and RPM, a Prony brake, or BMEP — with full step-by-step working.
Compression Ratio Calculator
Calculate engine compression ratio — or solve for bore, stroke, or clearance volume.
Engine CC to HP Calculator
Convert engine displacement to horsepower using four engineering methods.
Engine Displacement Calculator
Calculate engine displacement, bore, stroke or cylinder count from any three variables.
Final Drive Ratio Calculator
Solve ring/pinion ratios, vehicle speed, engine RPM and tyre size in one tool.
Fuel Injector Size Calculator
Find the right injector size for your target horsepower in seconds.
Horsepower to Torque Calculator
Convert between horsepower, torque and RPM with full step-by-step working.
Intercooler Calculator
Calculate charge-air temperature drop, pressure loss, density gain and estimated power increase from your intercooler.
Quarter-Mile Calculator
Predict your drag-strip ET and trap speed from horsepower and weight.
Tire Diameter Calculator
Find overall diameter, sidewall, circumference and revs/mile — plus speedometer correction when swapping sizes.
Tire Size Calculator
Decode any P-metric tire code and compare two sizes in seconds.
Turbo Size Calculator
Find the right turbocharger for your engine — compressor flow, pressure ratio, inducer size and shaft speed.
Wheel Offset Calculator
Calculate backspacing, lip clearance and track change from ET offset.
0-60 mph Estimator
Estimate your car''s 0–60 mph time from weight and horsepower.
Boost Pressure Calculator
Convert boost gauge readings, solve pressure ratio, model charge-air density and check injector duty cycle — all in your browser.
Gear Ratio & Speed Calculator
Work out vehicle speed, RPM, gear ratios and final drive from tyre size and transmission data.
Speedometer Error Calculator
Find out how inaccurate your speedo really is — and what your true speed is.
Volumetric Efficiency Calculator
Measure how well your engine breathes — four methods, instant results.
Music & Audio
BPM to Milliseconds Calculator
Turn any tempo into delay and note-length times in milliseconds.
Note Frequency Calculator
Find the exact frequency in Hz for any musical note and octave.
Speaker Box Volume Calculator
Design sealed and ported enclosures using Thiele-Small parameters.
Speaker Impedance Calculator
Calculate total impedance for series, parallel and mixed speaker wiring in seconds.
Subwoofer Port Length Calculator
Calculate the exact port tube length to hit your target bass tuning frequency.
BPM to Milliseconds Calculator
Convert any tempo to exact delay, echo and reverb times — straight, dotted and triplet.
Capo Transpose Calculator
Find the right capo fret and open chord shape for any key — instantly.
Cents to Frequency Calculator
Convert pitch intervals in cents to exact frequencies — and back.
Chord Finder
Build any chord by root and type, or identify a chord from its notes — with audio playback.
Guitar String Tension Calculator
Find the exact tension on every string — or the right gauge for a target feel.
Key Transpose Calculator
Transpose any song to a new key instantly — diatonic chords, scale notes and full chord charts.
Semitone Interval Calculator
Pick any two notes and instantly see the semitone distance, cents, frequency ratio and interval name.
Time Signature Calculator
Beat durations, bar lengths, compound vs simple meters, polyrhythm grids and tap tempo — all in one tool.
BPM Delay Calculator
Convert BPM to delay times, reverse-engineer tempo from a known delay, tap-detect tempo and model feedback decay — all in one tool.
Metronome & BPM Tapper
Tap the beat, measure your tempo, and hear a precise click-track with note-delay tables.
Scale Degree Calculator
Instantly see every note, Roman numeral and interval in any musical scale.
Gaming
Italy Codice Fiscale Decoder & Validator
Decode an Italian Codice Fiscale — date of birth, gender and check digit.
Dice Notation Roller
Roll full RPG dice notation: 3d6+2, 2d20kh1, 4d6dl1, exploding dice and more.
D&D Ability Score Calculator
Roll, buy, or array-assign your D&D 5e stats with modifiers, saving throws and XP thresholds.
Character Level Calculator
Instantly find your RPG character level from XP — D&D 5e, Pathfinder 2e and OSE.
Damage Per Second (DPS) Calculator
Calculate true DPS for any weapon, build or ability rotation in any game.
D&D 5e Encounter XP Calculator
Balance encounters by difficulty — Easy, Medium, Hard or Deadly.
D&D Spell Slot Tracker
Track every spell slot for every D&D 5e caster class in real time.
Experience Points (XP) Calculator
Build D&D 5e encounters, look up level-up thresholds and track character XP — all in one tool.
Loot Roll Generator
Simulate RPG loot tables with weighted drops, rarity tiers, and dice quantities.
MTG Life Counter
Track life totals, poison counters, commander damage and more for Magic - The Gathering.
D&D Critical Hit Calculator
Instantly see crit damage range, average, and full probability distribution.
Dice Probability Calculator
Exact probabilities for any dice roll — 2d6, 3d10, custom polyhedral dice.
Astronomy
Moon Phase Calculator
Find the moon phase and illumination for any date.
Astronomical Unit Converter
Convert astronomical units (AU) to kilometers and back.
Light-Years to Kilometers Converter
Convert light-years to kilometers and back.
Parsecs to Light-Years Converter
Convert parsecs to light-years and back.
Planet Weight Calculator
See how much you would weigh on every planet, the Moon and the Sun.
Telescope Magnification Calculator
Find your telescope magnification from focal length and eyepiece.
Sunrise & Sunset Calculator
Find exact sunrise, solar noon, and sunset times for any location and date.
Golden Hour Calculator
Find the exact golden hour and blue hour windows for any location and date.
Blue Hour Calculator
Find exact blue hour, golden hour and twilight times for any location and date.
Next Full Moon Calculator
Find the exact date and time of the next full moon — and the ones after it.
Sunrise & Sunset Time Calculator
Find exact sunrise, sunset, solar noon and golden hour for any location and date — no internet needed.
Telescope Magnification Calculator
Magnification, exit pupil, true FOV, limiting magnitude and resolving power — all in one tool.
Angular Resolution Calculator
Rayleigh criterion, Dawes limit, Abbe limit, pixel scale and more — all in your browser.
Day Length Calculator
Sunrise, sunset, golden hour and day length for any location and date — no internet required.
Focal Ratio Calculator (f-number / f-stop)
Calculate f-number, focal length, aperture diameter, depth of field and exposure equivalents.
Light-Year Distance Calculator
Convert cosmic distances between light-years, parsecs, AU, km and more — with light travel time.
Moon Phase Tonight
See the current moon phase, illumination, distance and next phase dates — instantly.
Redshift Calculator
Compute cosmological distances, lookback time and recession velocity from redshift z.
Solar Noon Calculator
Find the exact moment the sun peaks in the sky — plus sunrise, sunset and golden hour.
Star Magnitude Calculator
Compare star brightness, find absolute magnitude, and compute telescope limits.
Geography & GPS
3D Distance Calculator
Find the straight-line distance between two points in three-dimensional space.
Haversine Distance Calculator
Calculate the great-circle distance between any two points on Earth.
Latitude & Longitude Converter
Convert coordinates between DD, DDM, DMS, radians and UTM — plus great-circle distance and bearing.
Bearing Calculator
Find the compass bearing and great-circle distance between any two points on Earth.
Compass Bearing Calculator
Find the true bearing and great-circle distance between any two points on Earth.
Coordinate Distance Calculator
Great-circle distance, bearing and midpoint between two GPS coordinates.
GPS Coordinate Formatter
Convert GPS coordinates between DD, DDM, DMS, UTM, Geohash, Plus Code, Maidenhead and MGRS instantly.
Great-Circle Distance Calculator
Compute the shortest path between any two points on Earth — with bearings, midpoint, and Vincenty precision.
Map Scale Calculator
Convert map distances to real-world distances — and find any unknown in the scale equation.
UTM Coordinate Converter
Convert between UTM grid references and latitude/longitude in both directions.
Statistics & Probability
Combinations & Permutations Calculator
Compute nCr, nPr, and factorials instantly in your browser.
Z-Score Calculator
Convert a value to a standard score — and back.
Confidence Interval Calculator
Mean ± margin of error at 80–99% confidence.
Correlation Calculator
Pearson r for two paired data series.
Probability Calculator
Complement, AND/OR for independent events, and Bayes.
Sample Size Calculator
How many responses you need for a survey.
Statistics Calculator
Paste numbers and get mean, median, mode, range, variance, standard deviation, quartiles and sum instantly.
Standard Deviation Calculator
Sample and population standard deviation with a full step-by-step working table.
Permutation and Combination Calculator
Compute nPr and nCr with a full factorial breakdown and exact big-number math.
Expected Value Calculator
Calculate E[X] for discrete, Bernoulli, uniform and normal distributions — with full working shown.
Kelly Criterion Calculator
Find the mathematically optimal bet size to maximise long-run bankroll growth.
Linear Regression Calculator
Fit a least-squares line, get R², ANOVA table, residuals and predictions instantly.
P-Value Calculator
Instantly compute exact p-values for Z, t, and chi-squared tests — with formula working shown.
Poisson Distribution Calculator
Calculate exact, cumulative and range probabilities for any Poisson process.
Binomial Probability Calculator
Exact P(X = k), cumulative CDF and full distribution — with a bar chart.
Combinations with Repetition Calculator
Count multiset selections using the stars-and-bars formula.
Correlation Coefficient Calculator
Calculate Pearson r, R², regression line and scatter plot instantly.
Z-Score to Percentile Calculator
Convert any z-score to a percentile — or find the z-score for any percentile.
Birthday Paradox Calculator
Discover how quickly shared birthdays become probable in a group.
Geometry
Circle Calculator
Radius, diameter, circumference and area from any one value.
Triangle Calculator
Area, perimeter and angles from three side lengths.
Pythagorean Theorem Calculator
Solve a² + b² = c² for the hypotenuse or a missing leg.
Body Surface Area Calculator
BSA in m² by Du Bois, Mosteller and Haycock formulas.
Sphere Calculator
Volume and surface area of a sphere from its radius.
Cone Calculator
Volume, surface area and slant height of a right circular cone.
Cylinder Calculator
Volume and surface area of a right circular cylinder.
Pyramid Calculator
Volume and surface area of a rectangular-base pyramid.
Trapezoid Calculator
Area, perimeter and midsegment of a trapezoid.
Ellipse Calculator
Area, perimeter, eccentricity and axes of an ellipse.
Polygon Area Calculator
Area, perimeter and angles of any regular polygon.
Hexagon Calculator
Area, perimeter, diagonals and apothem of a regular hexagon.
Sector & Arc Calculator
Arc length, sector area and chord from radius and angle.
Parallelogram Calculator
Area, height, perimeter and diagonals of a parallelogram.
Right Triangle Trig Solver
Solve any right triangle from two known values — sides and angles.
Law of Cosines Calculator
Solve any triangle from three sides or two sides and an angle.
Pentagon Calculator
Area, perimeter, diagonal and radii of a regular pentagon.
Octagon Calculator
Area, perimeter, diagonals and radii of a regular octagon.
Rhombus Calculator
Area, perimeter, diagonals and angles of a rhombus.
Regular Polygon Calculator
Area, perimeter, radii and angles for any regular n-gon.
Annulus Calculator
Area, width and circumferences of a ring between two circles.
Ramp Slope Calculator
Angle, percent grade, rise/run ratio and ADA compliance — instantly.
Rise Over Run Calculator
Slope, angle, grade and pitch from any rise and run — or solve in reverse.
Cube Volume Calculator
Instantly find the volume, surface area and diagonals of any cube — solve from any known value.
Ellipsoid Volume Calculator
Compute volume, surface area and solve for any semi-axis — all in your browser.
Equilateral Triangle Calculator
Instantly find side, height, area, perimeter, inradius and circumradius — solve from any one value.
Pyramid Volume Calculator
Volume, surface area and slant height for any pyramid — square, rectangular, triangular or hexagonal base.
Rectangular Prism Volume Calculator
Instantly find volume, surface area and space diagonal — or solve for any missing dimension.
Right Triangle Calculator
Solve any right triangle from two known values — sides, angles, area and trig ratios instantly.
Slope-Intercept Calculator
Find the equation y = mx + b from two points, solve for x or y, and see the diagram.
Sphere Volume Calculator
Instantly find volume, surface area, diameter or radius — solve for any variable.
Triangle Area Calculator
Find the area of any triangle: base-height, Heron's formula, SAS, or coordinates.
Hexagon Area Calculator
Find the area of a regular hexagon from any measurement you have.
Circle Diameter Calculator
Find diameter, radius, circumference and area — solve from any one value.
Cone Volume Calculator
Calculate cone volume — or solve for radius or height from a known volume.
Rhombus Area Calculator
Find rhombus area from diagonals, side + height, or side + angle — with full working.
Torus Volume Calculator
Find volume, surface area and all torus dimensions — solve for any variable.
Trapezoid Area Calculator
Instantly find the area of any trapezoid — or solve for any missing dimension.
Triangle Angle Calculator
Find every angle and side of any triangle from three known values.
Annulus Area Calculator
Find the ring area, or solve for outer or inner radius from a known area.
Arc Length Calculator
Find arc length, radius or central angle — with working steps and a live diagram.
Capsule Volume Calculator
Calculate capsule volume — or solve for radius or cylinder height from a known volume.
Circle Area Calculator
Area, radius, diameter and circumference — solve for any one from any other.
Circle Equation Calculator
Find the standard form, general form, area, arc length, chord and sector — instantly.
Cylinder Volume Calculator
Find volume, surface area or a missing dimension of any cylinder instantly.
Ellipse Area Calculator
Compute ellipse area, perimeter, eccentricity — or solve for any missing semi-axis.
Frustum Volume Calculator
Find the volume of a truncated cone — or solve back for height or radius.
Hemisphere Volume Calculator
Calculate the volume, curved surface area and base area of any hemisphere instantly.
Heron's Formula Calculator
Find the area of any triangle from its three side lengths — no angles needed.
Law of Sines Calculator
Solve any triangle from two angles + one side, or two sides + an opposite angle.
Octagon Area Calculator
Area, perimeter, diagonals and radii of a regular octagon — solved from any measurement.
Parallelogram Area Calculator
Find the area of any parallelogram — or solve for base or height — instantly.
Regular Polygon Area Calculator
Area, perimeter, radii and angles for any regular n-gon — solve from side, radius or perimeter.
Sector Area Calculator
Area, arc length, chord and perimeter from any two of: radius, angle, or area.
Tetrahedron Volume Calculator
Calculate the volume of a regular tetrahedron — or find the edge length from a known volume.
Triangular Prism Volume Calculator
Find the volume (and surface area) of any triangular prism instantly.
Circle Circumference Calculator
Circumference from radius, diameter or area — solve any way around.
Pentagon Area Calculator
Area, perimeter, inradius, circumradius and diagonal — solve from any measurement.
Sphere Surface Area Calculator
Find the surface area of any sphere — or back-calculate the radius from a known area.
Diagonal of a Rectangle Calculator
Find the diagonal, width, height, angles, area and perimeter — with full step-by-step working.
Law of Cosines Solver
Solve any triangle from any three pieces — all five congruence cases with full step-by-step working.
Perimeter Calculator
Instantly find the perimeter of 14 shapes with step-by-step working.
Surface Area Calculator
Instant surface area for 10 shapes — sphere, cylinder, cone, prism, pyramid, torus and more.
Unit Circle Calculator
Enter any angle and instantly read sin, cos, tan, csc, sec, cot — with a live diagram.
Math & Algebra
Fraction to Decimal Converter
Turn any fraction — proper, improper or mixed — into a decimal.
Decimal to Fraction Converter
Convert any decimal into its simplest fraction or mixed number.
Mean, Median & Mode Calculator
Get the mean, median, mode, range and sum of any list of numbers.
Quadratic Formula Solver
Solve ax² + bx + c = 0 for real or complex roots.
Percentage Change Calculator
Work out the percentage increase or decrease between two values.
Business Days Calculator
Count working days between two dates, holidays excluded.
CGPA to Percentage Calculator
Convert CGPA to a percentage using CBSE, VTU, or a custom multiplier.
Romania CNP Decoder
Decode birth date, sex and county from a Romanian CNP.
Percentage of a Number Calculator
Quickly find what a percentage of any number is.
Tip Percentage Table
See the tip and total for a bill across every common tip percentage at once.
Percentage Increase / Decrease Calculator
Find the % change between two numbers, or apply a % rise or fall.
Proportion Solver (Cross-Multiplication)
Solve a/b = c/d for the missing value by cross-multiplication.
Exponent Calculator (Power Calculator)
Raise any base to any power — including negative and fractional exponents.
Logarithm Calculator (log, ln, log₂, any base)
Compute log base 10, natural log, log base 2 or any custom base.
Factorial Calculator (n!)
Compute exact factorials of any non-negative integer with BigInt.
Time Duration Adder
Add and subtract hours, minutes and seconds across a list of durations.
2x2 Matrix Calculator
Add, subtract, multiply, and find the determinant or inverse of 2x2 matrices.
Prime Factorization Calculator
Break any whole number down into its prime factors instantly.
Percentage of Total Calculator
Turn a list of values into each value's share of the total.
Cubic Meters to Liters Converter
Convert m³ to liters (and back) instantly.
Acceleration Calculator
a = (v_f − v_i) ÷ t — solve for acceleration, velocity, or time.
Percentile Calculator
Find any percentile of a data set — or a value's rank.
Degrees to Radians Converter
Convert degrees to radians instantly — rad = ° × π ÷ 180. Free, browser-only.
Radians to Degrees Converter
Convert radians to degrees instantly — ° = rad × 180 ÷ π. Free, browser-only.
Percentage Difference Calculator
Find the percentage difference between two values.
Weighted Average Calculator
Average values that carry different weights.
Rounding Calculator
Round numbers to decimals, multiples or whole numbers.
Add Business Days
Add or subtract business days from a date, skipping weekends.
2D Vector Calculator
Add, subtract, dot, cross and find the angle between 2D vectors.
Complex Number Calculator
Add, subtract, multiply and divide complex numbers with modulus and argument.
Set Operations Calculator
Union, intersection, difference and symmetric difference of two sets.
Modular Exponentiation Calculator
Compute (base ^ exponent) mod modulus for huge numbers.
Percentage to GPA Converter
Convert a percentage grade to a 4.0-scale GPA and letter.
Class Rank Percentile Calculator
Turn your class rank into a percentile and top-percent figure.
Attendance Percentage Calculator
Check your attendance percentage and absences left.
Debt-to-Income Ratio Calculator
See your DTI ratio and where you stand with lenders.
Decision Matrix Maker
Score options against weighted criteria and find the ranked winner.
Date Duration Calculator
Exact years, months, days and hours between two dates — plus add or subtract a duration.
Roman Numeral Math Calculator
Add, subtract, multiply and divide directly in Roman numerals — with a full step-by-step explanation.
Math Worksheet Generator
Build printable arithmetic worksheets with a matching answer key.
Aspect Ratio Crop & Letterbox Calculator
Convert any resolution to a new aspect ratio: crop, letterbox, area kept and storage cost.
Debt-to-Income Ratio Calculator
Add up your monthly debts and income to see your DTI and where it lands with lenders.
GCD & LCM Calculator
Find the greatest common divisor and least common multiple of any integers — with Euclid steps.
Ratio Calculator
Simplify ratios, solve proportions and scale ratios — with the working shown.
Fraction Calculator
Add, subtract, multiply and divide fractions with full working shown.
Percentage Calculator
One tool for every percentage question — of, is-what-%, change, difference, increase, decrease and reverse.
Prime Number Checker
Test any number for primality, factorise it, and list every prime up to N.
Scientific Notation Converter
Convert decimals to scientific, engineering and E-notation with significant figures.
Quadratic Equation Solver
Enter a, b, c and get the roots, discriminant, vertex, axis and full working.
Cold Brew Ratio Calculator
Perfect your coffee-to-water ratio, yield, servings and caffeine estimate.
Compost Ratio Calculator
Find the perfect carbon-to-nitrogen ratio for fast, odour-free composting.
Espresso Ratio Calculator
Dial in the perfect brew ratio, extraction yield and TDS for every shot.
Kombucha Ratio Calculator
Perfect your 1F brew ratios and 2F carbonation sugar — batch-size aware.
Dot Product Calculator
Compute dot products, angles, projections and cross products for 2D–5D vectors.
Matrix Determinant Calculator
Find the determinant of any 2×2 to 6×6 matrix with full step-by-step working.
Modular Exponentiation Calculator
Compute (a^b) mod m instantly — even for enormous cryptographic-size exponents.
Exponential Growth & Decay Calculator
Solve N(t) = N₀·e^(rt) — find future value, initial value, rate, or time.
Matrix Multiplication Calculator
Multiply, invert, transpose or find the determinant of matrices up to 6x6.
Cross Product Calculator (3D Vectors)
Compute a × b instantly — magnitude, angle, area and unit normal.
Vector Magnitude Calculator
Find the length of any 2-D, 3-D or n-D vector, get the unit vector and direction angles.
Cubic Equation Solver
Find all three roots of ax³ + bx² + cx + d = 0 with full working shown.
Decimal to Fraction Calculator
Convert any decimal — including repeating decimals — to its exact simplest fraction, with full step-by-step working.
Big Factorial Calculator — Exact BigInt Up to 10,000!
Compute exact factorials with BigInt, digit counts, scientific notation and full working steps.
Fibonacci Calculator
Find any Fibonacci number instantly, explore the golden ratio, and visualise the spiral.
Fraction to Percent Calculator
Convert any fraction, mixed number, or decimal to a percentage instantly.
Geometric Sequence Calculator
Find any term, the common ratio, or the sum of a geometric sequence instantly.
Greatest Common Factor Calculator
Find the GCF of two or more numbers with full prime-factor working and Euclid steps.
Percent Off Calculator
Find the sale price, saving, or original price for any discount instantly.
Quadratic Formula Calculator
Solve ax² + bx + c = 0 instantly — real and complex roots, full working, parabola diagram.
Simplify Fraction Calculator
Reduce any fraction to its lowest terms instantly, with full working shown.
System of Equations Solver
Solve 2x2 and 3x3 linear systems instantly with full working steps.
Least Common Multiple Calculator
Find the LCM of any list of integers — with prime-factor table, step-by-step working, and a cycle diagram.
Arithmetic Sequence Calculator
Find any term, the sum, or a missing value in an arithmetic sequence.
Cross-Multiplication Calculator
Solve any proportion instantly — enter three values, get the fourth.
Percent Error Calculator
Find the percent error between a measured and accepted value — or solve backwards.
Proportion Calculator
Solve any missing value in a/b = c/d instantly using cross-multiplication.
Summation Calculator
Compute sigma notation sums instantly — custom expressions, arithmetic, geometric, power, and harmonic series.
WACC Calculator
Compute the Weighted Average Cost of Capital with CAPM equity cost and the full tax shield.
Angle Between Vectors Calculator
Find the angle between any two 2-D, 3-D, or 4-D vectors — with full working.
Sine, Cosine & Tangent Calculator
Compute all six trig functions, inverses, unit-circle coordinates and wave graphs instantly.
Cartesian to Polar Calculator
Convert (x, y) to (r, θ) — or reverse — with full working and unit options.
Degrees to Radians Calculator
Convert degrees to radians, see trig values, arc length, sector area and angular motion — all in one tool.
Inverse Trig Calculator
Find angles from ratios — arcsin, arccos, arctan, arccot, arcsec, arccsc and the hyperbolic inverses.
Polar to Cartesian Calculator
Convert polar (r, θ) to Cartesian (x, y) — or reverse — instantly with step-by-step working.
Radians to Degrees Calculator
Convert any angle — see the formula, trig values, DMS and unit-circle coordinates instantly.
Trigonometric Identity Calculator
Verify and evaluate every major trig identity — basic, Pythagorean, double-angle, half-angle, sum-difference, product-to-sum, power-reduction, co-function and inverse.
Brine Ratio Calculator
Find the exact salt-to-water ratio for any brine: pickling, curing, fermentation or food-science.
Coffee-to-Water Ratio Calculator
Get the perfect coffee ratio for any brew method — pour-over, espresso, French press and more.
Ganache Ratio Calculator
Get the exact chocolate-to-cream ratio for truffles, glazes, tarts and more.
Rice Water Ratio Calculator
Perfect rice every time — correct water for any rice type, method and altitude.
Golden Ratio Typography Calculator
Generate a perfect type scale, line heights and measure using φ = 1.618.
Modular Scale Calculator
Generate harmonious type and spacing scales from a base size and musical ratio.
Time Duration Between Two Dates Calculator
Find the exact duration between any two dates — in years, months, days, hours, minutes and seconds.
Food, Cooking & Brewing
Cooking Measurement Converter
Convert cups, tablespoons, teaspoons, ml and litres for recipes.
Oven Temperature Converter
Convert oven temperatures between °C, °F and gas mark.
Recipe Scaler
Scale a recipe up or down by servings, ingredient by ingredient.
Slow Cooker Time Converter
Convert oven or stovetop times into slow cooker Low and High times.
Yeast Conversion Calculator
Convert between fresh, active dry and instant yeast.
Recipe Cost Calculator
Work out the true cost per serving of any recipe — pack price in, plate cost out.
Cooking Unit Converter
Convert cups, tablespoons, grams and millilitres — density-aware, and scale whole recipes.
Cooking Weight to Volume Converter
Convert grams to cups, tablespoons and teaspoons for any ingredient.
Oven Temperature Converter
Convert between Celsius, Fahrenheit and gas mark with a full reference table.
Beer ABV Calculator
Calculate alcohol by volume, apparent attenuation and calories from OG and FG.
Beer IBU Calculator
Calculate bitterness (IBUs) from hop additions using Tinseth or Rager.
Mash Efficiency Calculator
Know exactly how well your mash converted grain sugars to wort — batch after batch.
Mead ABV Calculator
Find the alcohol content of your mead from original and final gravity readings.
Pizza Dough Calculator
Exact ingredient weights for any number of balls, size, and hydration.
Priming Sugar Calculator
Bottle carbonation sugar amounts for any beer style, volume and temperature.
Wine ABV Calculator
Calculate wine alcohol content from starting and ending specific gravity.
Keg Size Calculator
Convert any keg volume and find out exactly how many pints you will pour.
Meat Curing Calculator
Precise salt, curing salt and sugar amounts for dry or wet cures.
Turkey Cooking Time Calculator
Get the exact cook time, rest time and oven start time for your turkey.
Ham Cooking Time Calculator
Exact oven times for any size ham — bone-in, boneless, fresh or pre-cooked.
Wine Bottles Per Guest Calculator
Find out exactly how many bottles of wine to buy for any event.
Sous Vide Time & Temperature Calculator
Find the exact bath temperature and minimum safe cooking time for any protein.
Butter Conversion Calculator
Convert butter between grams, ounces, cups, sticks, tablespoons and more — with full working shown.
Cooking Temperature Converter
Instantly convert oven temperatures between Celsius, Fahrenheit, Kelvin and UK Gas Mark.
Egg Substitute Calculator
Find the best vegan or allergy-friendly egg replacement for any recipe.
Yeast Conversion Calculator
Convert between active dry, instant, fresh cake, and sourdough starter — instantly.
Slow Cooker Conversion Calculator
Convert any oven or stovetop recipe to slow cooker settings in seconds.
Farming & Garden
Grass Seed Calculator
Work out how much lawn seed you need — and what it will cost.
Aquarium Volume Calculator
Find your tank volume in litres, US gallons and UK gallons — five shapes supported.
Garden & Raised-Bed Soil Volume Calculator
Find out exactly how many litres (or bags) of compost or topsoil your raised bed needs.
Plant Spacing Calculator
Find exactly how many plants fit your bed — square or triangular grid.
Hydroponic Nutrient Calculator
Calculate exact salt weights for any reservoir volume and EC target.
Pond Volume Calculator
Calculate pond volume, liner size, pump output, fish stocking and treatment doses.
Fertilizer NPK Calculator
Calculate nutrients delivered, required application rates, and bags needed from any NPK grade.
Seeding Rate Calculator
Calculate the exact kg/ha or lb/acre seeding rate for any crop — and back-calculate population, TSW or establishment.
Chicken Feed Calculator
Daily feed, water, and nutrient needs for any chicken type — layers, broilers, pullets, and more.
Crop Yield Calculator
Calculate yield per hectare or acre from any harvest quantity and field area.
Greenhouse Heating Calculator
Size your greenhouse heater in seconds — fabric loss, infiltration and all.
Irrigation Water Calculator
Calculate gross irrigation requirements, water volumes, and flow rates for any crop and field.
Stocking Density Calculator
Calculate animals per area or biomass per volume — with welfare band assessment.
Hay Bale Calculator
Calculate bale volume, dry matter and how many bales your livestock need.
Livestock Feed Calculator
Calculate daily feed, energy and protein requirements for cattle, sheep, pigs and poultry.
Silage Calculator
Clamp volume, field yield, DM tonnage and feeding days — all in one tool.
Home & DIY
Paint Calculator
How much paint to buy for any room — walls, coats and openings.
Tile Calculator
How many tiles to buy for a floor or wall, including waste.
Flooring Calculator
How many packs of laminate, vinyl or wood flooring to buy.
Concrete Calculator
Concrete volume and number of bags for a slab or footing.
Mulch Calculator
How much mulch, bark or compost to cover a garden bed.
Brick Calculator
Estimate how many bricks a wall needs, with a waste allowance.
Gravel Calculator
Work out the volume and weight of gravel for any area.
Fence Calculator
Count the posts, panels and rails for a fence run.
BTU Air Conditioner Calculator
Size an AC unit by working out the BTU your room needs.
Roof Pitch Calculator
Convert between rise/run, angle, percent and x-in-12 pitch.
BTU to kWh Converter
Convert BTU to kilowatt-hours and back, instantly.
Mulch & Soil Calculator
Bed size + depth → cubic yards or metres, bags needed and total cost.
Stairs Calculator
Turn total rise and run into steps, riser height, tread depth and stringer length — with building-code checks.
BTU Calculator
Size heating and cooling: room BTU plus the right air-conditioner.
Wallpaper Calculator
How many rolls of wallpaper you need — pattern repeat and cost included.
Fence and Gate Calculator
Run length, post spacing and gates to posts, panels, rails, concrete and cost.
Roof Area Calculator
Turn a building footprint and roof pitch into actual roof surface area, materials and cost.
Crushed Stone Calculator
Area, depth and material density to tonnes, bags and cost.
Asphalt Calculator
Turn area, depth and mix density into tonnes of asphalt — plus a cost estimate.
Flooring Calculator (Multi-Room, with Cost)
Packs of laminate, hardwood or vinyl across every room — plus cost and waste.
Pool Volume Calculator
Work out your pool volume in litres and gallons, plus chlorine dosing.
Brick Calculator
Wall area + brick size + mortar joint → bricks, mortar bags and cost.
Deck Building Calculator
Turn deck size into a board, joist and screw count — with a cost estimate.
Solar Panel Calculator
Size a solar array from your energy use or roof area — panels, output and savings.
Insulation Calculator
Area + target R-value + pack coverage → packs, rolls and cost.
Carpet Calculator
How much carpet to buy from a fixed-width roll — with waste, stairs and cost.
Drywall Calculator
Sheets of plasterboard, screws, compound and tape — with a cost estimate.
Paint Calculator
Wall area minus doors and windows, coats and coverage, to paint and cost.
3D Print Time & Material Estimator
Estimate print time, filament usage and material cost from model volume, infill and speed.
3D Print Filament Cost Calculator
Find the exact material cost of any print from grams used and spool price.
Board Foot Calculator
Instantly calculate board feet from lumber dimensions and get a material cost estimate.
Crochet Hook Size Converter
Instantly convert crochet hook sizes between US, UK and metric (mm).
Fabric Yardage Calculator
Enter your pattern pieces, pick a bolt width, and get the exact yardage to buy.
Knitting Gauge Calculator
Work out cast-on stitches and rows from your gauge swatch and target size.
Quilt Binding & Backing Calculator
Know exactly how much fabric to buy for binding and backing before you cut a single strip.
Resin 3D Print Cost Calculator
Find the exact material cost of any MSLA or DLP resin print from mL used and bottle price.
Yarn Yardage Calculator
Find exactly how many yards — and skeins — your knitting or crochet project needs.
Candle Wax Calculator
Work out exactly how much wax, fragrance oil and dye you need for any batch.
Epoxy Resin Calculator
Calculate exact Part A and Part B volumes for any mould shape and mix ratio.
Firewood Cord Calculator
Convert stack dimensions to full cords, face cords, BTU and seasonal cost.
Kerf Calculator
Calculate material loss from saw cuts and plan your cut list precisely.
Soap Lye Calculator
Calculate exact NaOH or KOH lye amounts for cold-process and liquid soapmaking.
Wood Shrinkage Calculator
Predict exact dimension loss as lumber dries from green to target moisture content.
Finance & Money
UK Mortgage Calculator
Work out monthly repayments, total interest and overpayment savings.
Compound Interest & Savings Calculator
Project savings growth with regular deposits and compound interest.
Free Invoice Generator
Build a branded invoice with line items, tax and totals, then export a clean PDF.
Loan & Personal Credit Calculator
Monthly payment, total cost of credit and representative APR.
Loan Comparison Tool
Compare up to 3 loans side by side — payment, total interest and a balance chart.
Tip Calculator & Bill Splitter
Split the bill, add a tip, round up and share the result.
Currency Converter
Convert between major currencies with live exchange rates.
Monthly Budget Planner
Track income and expenses, see your savings rate, and get a live spending chart.
Pakistan Salary Income Tax Calculator (FY 2024-25)
Monthly take-home after Pakistan income tax — salaried slabs for FY 2024-25.
Savings Goal Calculator
How much to save each month — or how long it takes.
ROI Calculator
Return on investment, net gain and annualised ROI.
Debt Snowball Calculator
See how fast extra payments clear your debts — snowball or avalanche.
Markup vs Margin Calculator
Convert between cost, price, markup and profit margin instantly.
Net Worth Calculator
Add up your assets and liabilities to find your net worth.
UAE Emirates ID Decoder & Validator
Decode a 15-digit Emirates ID — country prefix, birth year and Luhn check digit.
Simple Interest Calculator
Work out simple interest and the total amount on a deposit or loan.
APR Calculator
Find the true annual cost of a loan once fees are included.
Mortgage Overpayment Calculator
See how much interest and time a regular overpayment saves.
Loan Comparison Calculator
Compare two loans side by side to find the cheaper overall deal.
Salary to Hourly Converter
Convert pay between hourly, weekly, monthly and yearly in one place.
Future Value Calculator
Project the future value of savings with regular contributions and compounding.
Debt Avalanche Calculator
Pay off debt fastest — avalanche vs snowball, with a payoff order.
Investment Return Calculator
Project the future value of an investment with regular contributions.
Mortgage Affordability Calculator
See how much home you can afford from your income and deposit.
Amortization Schedule Generator
Full month-by-month payment breakdown for any loan.
Salary Raise Calculator
Turn a raise percentage into real money — after inflation.
Hourly to Annual Salary Calculator
Convert an hourly rate into yearly, monthly and weekly pay.
Sales Commission Calculator
Work out commission earnings from sales and rate — instantly.
Split Bill with Tax and Tip
Split a restaurant bill evenly including tax and tip.
Freelance Rate Calculator
Work out the hourly rate a freelancer needs to charge.
Debt Payoff Planner (Snowball vs Avalanche)
List your debts, compare snowball and avalanche, and see your debt-free date on a chart.
50/30/20 Budget Calculator
Split your take-home pay into needs, wants and savings.
Savings Rate Calculator
Find your savings rate and a rough years-to-FI estimate.
Refinance Break-Even Calculator
Find how long until a refinance pays for itself.
Mortgage Points Calculator
See if buying discount points is worth the up-front cost.
Coast FIRE Calculator
Find the portfolio you need today to coast to retirement.
Money Counter
Add up cash by counting notes and coins.
Expense Tracker
Log spending by category, see monthly totals and a category chart, then export to CSV.
Investment Scenario Comparison
Compare lump-sum, dollar-cost averaging and a mixed strategy side by side.
Tip Per Person Table
One bill and tip — see each person's share for any group size.
Salary Negotiation Modeler
Compare job offers side by side — base, bonus, equity and benefits as one total-comp number.
Savings Goal Tracker
Track multiple savings goals with progress bars and a projection chart.
Gross Rent Multiplier Calculator
Price relative to gross annual rent.
Coast FIRE Calculator (Pro)
See if your pot can coast to retirement, with a year-by-year chart.
Mortgage Overpayment Scenarios
Compare three overpayment strategies side by side on one mortgage.
Event Budget Planner
Plan event costs by category, track vendors and paid status, see the spend breakdown.
Net Worth Tracker
Log assets and liabilities over time and watch your net worth trend.
Debt-Free Date Calculator
See exactly when you'll be debt-free and how much interest you'll pay.
Group Expense Splitter
Add people and shared expenses, then see exactly who owes whom.
Savings Challenge Tracker
Run a 52-week or custom savings challenge, tick off weeks and watch your total grow.
Budget Forecaster
Turn recurring income and expenses into a 12-month projected balance chart.
Amortization Schedule Calculator
Loan amount, rate and term to a full month-by-month principal and interest table.
Invoice Tracker
Track who owes you, what is overdue, and your total outstanding — exportable to CSV.
Wedding Budget Planner
Track estimated vs actual costs, payments and your target — all in your browser.
Debt Snowball Tracker
Plan your debt payoff, compare snowball vs avalanche, and see the date you go debt-free.
Road Trip Cost Splitter
Plan a multi-leg road trip, total fuel, tolls and parking, then split fairly.
Freelance Project Quote Builder
Turn hours and rates into a polished client quote with deposit terms.
Sinking Fund Planner
Plan multiple savings goals and see exactly how much to set aside each month.
Multiplication Table Generator
Make printable times-table charts and blank practice worksheets, then export to PDF.
Car Loan Calculator
Monthly payment, total interest and a full schedule from price, deposit, trade-in, APR, term, fees and tax.
CAGR Calculator
Compound annual growth rate from a beginning and ending value.
Dividend Yield Calculator
Turn a share price and dividend into yield %, annual income and yield-on-cost.
Inflation Calculator
Convert money between two years and see how inflation erodes its buying power.
Rule of 72 Calculator
How long money takes to double — or the rate needed.
401(k) Calculator
Project your retirement balance from salary, contribution rate, employer match and returns.
Home Affordability Calculator
How much house can you afford? Income, debts and deposit to a max price.
Markup Calculator
Turn cost and markup into selling price, profit, and margin — or work it backwards.
Roth IRA Calculator
Project your tax-free retirement balance from contributions, years and return.
FIRE Number Calculator
Find your financial-independence target and how many years until you reach it.
Break-Even Calculator
Find how many units you must sell to cover your costs — with a chart.
Profit Margin Calculator
Cost and price to gross margin, markup, profit and break-even — with reverse solve.
Rent Affordability Calculator
Income, the 30% rule and your expenses — your recommended maximum rent.
Emergency Fund Calculator
Size your safety net and get a month-by-month plan to reach it.
Annuity Calculator
Calculate present value, future value, or periodic payment for any annuity.
Bond Price Calculator
Price a bond from its yield — or back-solve the YTM from a market price.
Bond Yield Calculator
Calculate YTM, bond price, duration, convexity and DV01 instantly.
Gross Profit Calculator
Calculate gross profit, gross margin %, and COGS ratio across multiple periods or product lines.
IRR Calculator
Find the Internal Rate of Return for any series of cash flows — instantly.
NPV Calculator
Calculate Net Present Value, IRR, payback period and a full discounted cash-flow schedule.
Perpetuity Calculator
Price any infinite stream of payments — ordinary, growing, or deferred.
Present Value Calculator
Discount any cash flow stream to today: lump sum, annuity, growing annuity, perpetuity.
Conversions & Units
Unit Converter
Convert length, weight, temperature, volume, area and speed instantly.
Acres to Hectares Converter
Convert ac to ha instantly — 1 ac = 0.4046856422 ha. Free, browser-only tool.
Acres to Square Metres Converter
Convert ac to m² instantly — 1 ac = 4046.856422 m². Free, browser-only tool.
Bar to PSI Converter
Convert bar to psi instantly — 1 bar = 14.50377378 psi. Free, browser-only tool.
Bytes to Kilobytes Converter
Convert B to KB instantly — 1 B = 0.001 KB. Free, browser-only tool.
Celsius to Fahrenheit Converter
Convert °C to °F instantly — °F = °C × 1.8 + 32. Free, browser-only tool.
Celsius to Kelvin Converter
Convert °C to K instantly — K = °C + 273.15. Free, browser-only tool.
Centimetres to Inches Converter
Convert cm to in instantly — 1 cm = 0.3937007874 in. Free, browser-only tool.
US Cups to Millilitres Converter
Convert cup to mL instantly — 1 cup = 236.5882365 mL. Free, browser-only tool.
Fahrenheit to Celsius Converter
Convert °F to °C instantly — °C = °F × 0.5555555556 − 17.77777778. Free, browser-only tool.
Feet to Metres Converter
Convert ft to m instantly — 1 ft = 0.3048 m. Free, browser-only tool.
US Gallons to Litres Converter
Convert gal to L instantly — 1 gal = 3.785411784 L. Free, browser-only tool.
Gigabytes to Megabytes Converter
Convert GB to MB instantly — 1 GB = 1000 MB. Free, browser-only tool.
Gigabytes to Terabytes Converter
Convert GB to TB instantly — 1 GB = 0.001 TB. Free, browser-only tool.
Grams to Ounces Converter
Convert g to oz instantly — 1 g = 0.03527396198 oz. Free, browser-only tool.
Hectares to Acres Converter
Convert ha to ac instantly — 1 ha = 2.471053815 ac. Free, browser-only tool.
Inches to Centimetres Converter
Convert in to cm instantly — 1 in = 2.54 cm. Free, browser-only tool.
Inches to Millimetres Converter
Convert in to mm instantly — 1 in = 25.4 mm. Free, browser-only tool.
Kilobytes to Bytes Converter
Convert KB to B instantly — 1 KB = 1000 B. Free, browser-only tool.
Kilobytes to Megabytes Converter
Convert KB to MB instantly — 1 KB = 0.001 MB. Free, browser-only tool.
Kelvin to Celsius Converter
Convert K to °C instantly — °C = K − 273.15. Free, browser-only tool.
Kilograms to Pounds Converter
Convert kg to lb instantly — 1 kg = 2.204622622 lb. Free, browser-only tool.
Kilograms to Stone Converter
Convert kg to st instantly — 1 kg = 0.1574730444 st. Free, browser-only tool.
Kilometres to Miles Converter
Convert km to mi instantly — 1 km = 0.6213711922 mi. Free, browser-only tool.
Kilometres per Hour to Knots Converter
Convert km/h to kn instantly — 1 km/h = 0.5399568035 kn. Free, browser-only tool.
Kilometres per Hour to Miles per Hour Converter
Convert km/h to mph instantly — 1 km/h = 0.6213711922 mph. Free, browser-only tool.
Knots to Kilometres per Hour Converter
Convert kn to km/h instantly — 1 kn = 1.852 km/h. Free, browser-only tool.
Pounds to Kilograms Converter
Convert lb to kg instantly — 1 lb = 0.45359237 kg. Free, browser-only tool.
Litres to US Gallons Converter
Convert L to gal instantly — 1 L = 0.2641720524 gal. Free, browser-only tool.
Litres to Millilitres Converter
Convert L to mL instantly — 1 L = 1000 mL. Free, browser-only tool.
Megabytes to Kilobytes Converter
Convert MB to KB instantly — 1 MB = 1000 KB. Free, browser-only tool.
Megabytes to Gigabytes Converter
Convert MB to GB instantly — 1 MB = 0.001 GB. Free, browser-only tool.
Metres to Feet Converter
Convert m to ft instantly — 1 m = 3.280839895 ft. Free, browser-only tool.
Miles to Kilometres Converter
Convert mi to km instantly — 1 mi = 1.609344 km. Free, browser-only tool.
Millilitres to US Cups Converter
Convert mL to cup instantly — 1 mL = 0.004226752838 cup. Free, browser-only tool.
Millilitres to Litres Converter
Convert mL to L instantly — 1 mL = 0.001 L. Free, browser-only tool.
Millimetres to Inches Converter
Convert mm to in instantly — 1 mm = 0.03937007874 in. Free, browser-only tool.
Ounces to Grams Converter
Convert oz to g instantly — 1 oz = 28.3495231 g. Free, browser-only tool.
PSI to Bar Converter
Convert psi to bar instantly — 1 psi = 0.0689475729 bar. Free, browser-only tool.
Square Feet to Square Metres Converter
Convert ft² to m² instantly — 1 ft² = 0.09290304 m². Free, browser-only tool.
Square Metres to Acres Converter
Convert m² to ac instantly — 1 m² = 0.0002471053815 ac. Free, browser-only tool.
Square Metres to Square Feet Converter
Convert m² to ft² instantly — 1 m² = 10.76391042 ft². Free, browser-only tool.
Stone to Kilograms Converter
Convert st to kg instantly — 1 st = 6.35029318 kg. Free, browser-only tool.
Terabytes to Gigabytes Converter
Convert TB to GB instantly — 1 TB = 1000 GB. Free, browser-only tool.
Area Calculator
Area of a rectangle, triangle, circle, trapezoid and more.
Volume Calculator
Volume of a box, sphere, cylinder, cone and more.
MPG to L/100km Converter
Convert miles-per-gallon to litres-per-100km and back, UK or US gallons.
Weighted Grade Calculator
Combine scores and category weights into a single weighted grade.
Julian to Gregorian Date Converter
Convert dates between the Julian and Gregorian calendars.
Hijri to Gregorian Converter
Convert an Islamic (Hijri) date to the Gregorian calendar.
Hebrew Calendar Converter
Convert a Gregorian date to the Hebrew (Jewish) calendar.
Persian (Jalali) Calendar Converter
Convert between Gregorian and Persian (Solar Hijri / Jalali) dates.
Ethiopian Calendar Converter
Convert between Gregorian and Ethiopian (Ge'ez) dates.
Thai Buddhist Date Converter (BE ⇄ CE)
Convert between Gregorian dates and the Thai Buddhist Era (พ.ศ.).
Nepali Bikram Sambat Converter (BS ⇄ AD)
Convert between Gregorian dates and the Nepali Bikram Sambat calendar.
Japanese Era Converter (Gengō / 和暦)
Convert between Gregorian dates and Japanese era years (Reiwa, Heisei…).
Coptic Calendar Converter (A.M. ⇄ Gregorian)
Convert between Gregorian dates and the Coptic calendar (Anno Martyrum).
Miles to Nautical Miles Converter
Convert mi to nmi instantly — 1 mi = 0.868976 nmi. Free, browser-only tool.
Celsius to Rankine Converter
Convert °C to °Ra instantly — °Ra = °C × 1.8 + 491.67. Free, browser-only tool.
Fahrenheit to Kelvin Converter
Convert °F to K instantly — K = (°F − 32) × 5/9 + 273.15. Free, browser-only.
Bits to Bytes Converter
Convert bits, bytes, kbit, KB, Mbit, MB, Gbit and GB — 1 byte = 8 bits.
File Size Converter
Convert B, KB, MB, GB, TB and binary KiB, MiB, GiB side by side.
Unit Price Comparison Calculator
Compare price per unit across pack sizes to find the best value.
Philippines TIN Validator
Check the structure of a Philippine tax ID number (TIN) instantly.
Grams to Kilograms Converter
Convert g to kg instantly — 1 kg = 1000 g. Free, browser-only tool.
Tonnes to Kilograms Converter
Convert t to kg instantly — 1 t = 1000 kg. Free, browser-only tool.
Yards to Meters Converter
Convert yd to m instantly — 1 yd = 0.9144 m. Free, browser-only tool.
Meters to Yards Converter
Convert m to yd instantly — 1 yd = 0.9144 m. Free, browser-only tool.
Miles to Yards Converter
Convert mi to yd instantly — 1 mi = 1760 yd. Free, browser-only tool.
Feet to Inches Converter
Convert ft to in instantly — 1 ft = 12 in. Free, browser-only tool.
Inches to Feet Converter
Convert in to ft instantly — 1 ft = 12 in. Free, browser-only tool.
Nautical Miles to Kilometers Converter
Convert nmi to km instantly — 1 nmi = 1.852 km. Free, browser-only tool.
Milliliters to Teaspoons Converter
Convert mL to US teaspoons (and back) instantly.
Milliliters to Tablespoons Converter
Convert mL to US tablespoons (and back) instantly.
Fahrenheit to Rankine Converter
Convert °F to °Ra (and back) instantly.
Square Kilometers to Square Miles Converter
Convert km² to mi² (and back) instantly.
Grams to Cups (Flour) Converter
Convert flour between grams and US cups by type.
Grams to Cups (Sugar) Converter
Convert sugar between grams and US cups by type.
Butter Converter
Convert butter between grams, ounces, cups, sticks and tablespoons.
Millilitres to Fluid Ounces Converter
Convert ml to US and UK fluid ounces, both ways.
Fuel Economy Comparison
Compare two vehicles by annual fuel cost — MPG or L/100km.
Frequency & Wavelength Calculator
Convert between frequency and wavelength for any wave.
Potential Energy Calculator
Gravitational PE = m·g·h — solve for energy, mass, or height.
Speed of Sound Calculator
Speed of sound in air at any temperature, plus travel time.
kWh to MJ Converter
Convert kilowatt-hours to megajoules and back, exactly.
Torque N·m to ft·lb Converter
Convert newton-metres to foot-pounds instantly — 1 ft·lb = 1.3558179 N·m. Free, browser-only.
Pascal to Bar Converter
Convert pascals to bar instantly — 1 bar = 100000 Pa. Free, browser-only.
Mbps to MB/s Converter
Convert internet speed in megabits to file transfer in megabytes per second.
Gbps to Mbps Converter
Convert gigabit per second link speeds to megabits per second.
Alcohol Units Calculator
UK units and US standard drinks from volume and ABV.
Rectangle Calculator
Area, perimeter and diagonal of a rectangle.
Sample Rate Converter
Find the resampling ratio between two audio sample rates.
Frame Rate Converter
Convert between video frame rates and frame counts.
Weeks to Days Converter
Convert weeks to days (and back) instantly.
Days to Hours Converter
Convert days to hours (and back) instantly.
Hours to Minutes Converter
Convert hours to minutes (and back) instantly.
Minutes to Seconds Converter
Convert minutes to seconds (and back) instantly.
Years to Months Converter
Convert years to months (and back) instantly.
Months to Weeks Converter
Convert months to weeks (and back) using the average month.
Kelvin to Fahrenheit Converter
Convert Kelvin to Fahrenheit and back.
Square Feet to Acres Converter
Convert square feet to acres and back.
Cups to Grams Rice Converter
Convert cups of rice to grams instantly — by rice type. Free, browser-only.
Tablespoons to Cups Converter
Convert tbsp to cups instantly — 1 cup = 16 tbsp. Free, browser-only tool.
US Quarts to Litres Converter
Convert qt to L instantly — 1 qt = 0.946352946 L. Free, browser-only tool.
US Pints to Millilitres Converter
Convert pt to mL instantly — 1 pt = 473.176473 mL. Free, browser-only tool.
US Gallons to Cups Converter
Convert gal to cups instantly — 1 gallon = 16 cups. Free, browser-only tool.
Fluid Ounces to Millilitres Converter
Convert fl oz to mL instantly — 1 fl oz = 29.5735 mL. Free, browser-only tool.
Water Intake by Body Weight Calculator
How much water to drink based on your weight.
Air Fryer Conversion Calculator
Convert any oven recipe to air fryer temperature and time.
Egg Size Substitution Calculator
Swap small, medium, large or jumbo eggs in any recipe.
International Shoe Size Converter
Convert shoe sizes between US, UK, EU and centimetres.
Hat Size Converter
Turn head circumference into US, UK, EU and S–XL hat sizes.
Bra Size Converter
Convert bra sizes between UK, US, EU, FR and AU/NZ.
Glove Size Converter
Convert hand circumference into numeric and S–XL glove sizes.
Belt Size Converter
Find your belt size from waist measurement in inches, cm or letters.
GPA to Letter Grade Converter
Turn a 4.0-scale GPA into its letter grade instantly.
Milligrams to Grams Converter
Convert mg to g instantly — 1 g = 1000 mg. Free, browser-only tool.
Micrograms to Milligrams Converter
Convert µg to mg instantly — 1 mg = 1000 µg. Free, browser-only tool.
Centimeters to Meters Converter
Convert cm to m instantly — 1 m = 100 cm. Free, browser-only tool.
Kilometers to Meters Converter
Convert km to m instantly — 1 km = 1000 m. Free, browser-only tool.
Millimeters to Centimeters Converter
Convert mm to cm instantly — 1 cm = 10 mm. Free, browser-only tool.
Miles per Gallon UK to US Converter
Convert fuel economy between UK and US miles per gallon.
Knots to MPH Converter
Convert knots to miles per hour, both directions.
Weekly Meal Planner and Shopping List
Plan a week of meals and auto-build a combined shopping list.
Unit Price Comparator
Compare products by price per kg, litre or item to find the best value.
PPI Calculator
Turn resolution and screen size into pixels-per-inch, dot pitch and a retina check.
Fuel Economy Converter
Convert MPG (US/UK), L/100km and km/L instantly, with a cost estimate.
Weighted Random Picker
Pick winners with custom odds — weighted, cryptographically fair, with live stats.
Power Converter
Convert watts, kilowatts, megawatts, horsepower, BTU/h and ft·lb/s.
Area Converter
Convert between mm², cm², m², hectares, km², acres, square feet and more.
Clothing Size Converter (US / UK / EU / IT)
Convert clothing sizes between US, UK, EU and Italian sizing for tops, dresses and jackets.
Shoe Size Converter
Convert shoe sizes between US, UK, EU and CM for men, women and kids.
Angle Converter
Convert between degrees, radians, gradians, turns, arcminutes and arcseconds.
Data Storage Converter
Convert bits, bytes, KB, MB, GB, TB and PB in decimal (1000) or binary (1024) mode.
Energy Converter
Convert joules, calories, watt-hours, BTU, foot-pounds and electronvolts.
Frequency Converter
Convert Hz, kHz, MHz, GHz, RPM and period (seconds) — type any field, the rest update live.
Length Converter
Convert between mm, cm, m, km, inches, feet, yards, miles and more — live.
Pressure Converter
Convert between Pa, kPa, bar, psi, atm, mmHg, torr and inHg instantly.
Speed Converter
Convert between m/s, km/h, mph, knots, ft/s and Mach instantly.
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine with exact formulas.
Time Unit Converter
Convert between nanoseconds, seconds, hours, days, weeks, months and years.
Torque Converter
Convert torque between N·m, kgf·m, lbf·ft, lbf·in and dyn·cm.
Volume Converter
Convert ml, litres, cubic metres, teaspoons, cups, pints, quarts and gallons (US and UK).
Weight & Mass Converter
Convert milligrams, grams, kilograms, tonnes, ounces, pounds, stones and tons in one live grid.
Ring Size Converter
Convert ring sizes between US, UK, EU, circumference and diameter.
Speed Distance Time Calculator
Enter any two of speed, distance, or time — instantly solve for the third.
Wavelength & Frequency Calculator
Convert wavelength, frequency and photon energy in any direction.
Julian Date Converter
Convert Gregorian dates to Julian Dates (JD, JDN, MJD) and back — instantly in your browser.
Celsius to Fahrenheit Converter
Instantly convert between °C, °F, Kelvin, Rankine and Réaumur — with formulas shown.
Kg to Pounds Converter
Instantly convert kilograms to pounds (and stones + pounds) — or reverse.
Fahrenheit to Celsius Converter
Instantly convert any temperature between °F and Celsius — with full working shown.
Grams to Ounces Converter
Instantly convert grams to ounces (and back) with the exact NIST factor.
Ounces to Grams Converter
Convert oz to g instantly — 1 oz = 28.3495 g. Free, browser-only tool.
Pounds to Kilograms Converter
Instantly convert lb to kg — decimal or stone+lb entry, full conversion grid.
Stone to Pounds Converter
Convert st to lb instantly — 1 stone = 14 pounds exactly. Free, browser-only tool.
Pounds to Stone Converter
Convert pounds to stones and pounds — with kilograms too.
Date & Time
Age Calculator
Your exact age in years, months and days — plus next-birthday countdown.
India PAN Card Decoder — Validate & Decode Your PAN
Decode every segment of an Indian PAN — holder type, name initial, and series.
Date Difference Calculator
Days, weeks and full calendar gap between any two dates.
Week Number Calculator
ISO 8601 and US week number for any date.
Add or Subtract Days Calculator
Add or subtract days, weeks, months or years from a date.
Day of the Week Finder
What day of the week was — or will be — any date.
Easter Date Calculator
Find the date of Easter Sunday for any year.
Age in Weeks and Days Calculator
Convert any age or date span into weeks and days.
Egypt National ID Decoder — Date of Birth, Governorate & Gender
Decode a 14-digit Egyptian National ID — century, date of birth, governorate and gender.
Age in Hijri Years Calculator
Convert your birth date to the Islamic calendar and get your age in Hijri years.
Ramadan Date Estimator
Estimate the Gregorian date Ramadan begins in any year.
Diwali Date Estimator
Find the date of Diwali (Lakshmi Puja) for any year.
Days Until a Date
Count how many days are left until any date — or how many have passed.
Weeks Between Two Dates
Count the number of weeks (and leftover days) between any two dates.
Age in Months and Days
Find an exact age in months and days from any birth date.
Next Birthday Countdown
See how many days until your next birthday and which weekday it falls on.
Dog Age Calculator
Convert your dog's age to human years by size and breed group.
Cat Age Calculator
Convert your cat's age to human years and life stage.
Days Alive Calculator
Find out exactly how many days you have been alive.
Age on Other Planets
See how old you would be on Mars, Jupiter and every other planet.
Countdown to New Year
Live countdown to midnight on 1 January in your local time.
Half-Birthday Calculator
Find your half-birthday — six months from the day you were born.
Data Cap Usage Calculator
Track data used against your monthly cap and project end-of-cycle usage.
Storage Needed Calculator
Estimate total storage for a batch of files from count and average size.
Work Days Between Dates
Count the working days between two dates, weekends excluded.
ISO Week Number Calculator
Find the ISO 8601 week number for any date.
Julian Day Number Calculator
Convert a calendar date to its Julian Day Number, JD and MJD.
Days in Month Calculator
How many days are in any month of any year?
Weekly Time Card Calculator
Add up a week of clock-in / clock-out times and breaks.
Age Gap Calculator
Find the age difference between two people.
Countdown to Christmas
Live days, hours, minutes and seconds until Christmas Day.
Countdown to Birthday
Live countdown to your next birthday from your date of birth.
Sprint Date Calculator
Generate agile sprint start and end dates from a cadence.
Mileage Log & Reimbursement Tracker
Log business trips and auto-calculate mileage reimbursement, with CSV export.
Printable Calendar Generator
Make a clean printable PDF calendar for any month or full year.
CCTV Storage Calculator
Size hard drives for a security camera system: cameras, resolution, retention.
Day of Week Calculator
Find any date's weekday, ISO week number, day-of-year and Julian Day Number — with step-by-step working.
Quarter of Year Calculator
Find which quarter any date falls in — with fiscal-year variants and progress bars.
Days Since Calculator
Find exactly how many days, weeks, months and years between any two dates.
Add Days to Date Calculator
Add or subtract any number of days from a date and see the full result instantly.
Days Until Birthday Calculator
Instantly see how many days until any birthday — with zodiac, birthstone, milestones and a live countdown.
Days Until Christmas Calculator
Exact days, sleeps, weeks and hours until Christmas Day — live, in your time zone.
Months Between Dates Calculator
Find the exact number of complete calendar months between any two dates.
Subtract Days from Date Calculator
Pick any date, enter a number of days, get the exact result instantly.
Weekly Time Card Calculator
Total your hours worked, split regular vs overtime, and calculate gross pay — all in one place.
Weeks Between Dates Calculator
Count the exact weeks (and leftover days) between any two dates instantly.
Working Hours Calculator
Add up daily shifts, subtract breaks, and compute gross pay with overtime.
Photo & Video
Download Time Calculator
Estimate how long a download takes from file size and connection speed.
Bandwidth Calculator
Estimate monthly bandwidth from page weight and visits per month.
Video File Size Calculator
Estimate a video file's size from duration and bitrate.
Audio File Size Calculator
Estimate audio file size for MP3, AAC or uncompressed WAV.
Upload Time Calculator
Estimate how long a file takes to upload at your real connection speed.
Depth of Field Calculator
Near/far limits, hyperfocal distance, solve-for-any-variable and full aperture comparison.
Hyperfocal Distance Calculator
Focal length, aperture and sensor CoC to maximum depth of field — solve any variable.
Crop Factor Calculator
Sensor size to crop factor, equivalent focal length and equivalent aperture — instant and precise.
More Calculators
Indonesia NIK (KTP) Decoder
Decode a 16-digit Indonesian NIK — province, date of birth and gender.
JAMB / Post-UTME / WAEC Aggregate Score Calculator
Work out your Nigerian university aggregate from JAMB, Post-UTME and O'level.
UK Statutory Entitlement Calculator (Maternity, Redundancy, Notice)
Work out Statutory Maternity Pay, redundancy pay and notice using 2025/26 rates.
Kenya Payslip & Net Pay Calculator (PAYE, SHIF, NSSF, Housing Levy)
Net pay after PAYE, SHIF, NSSF and the Affordable Housing Levy, explained.
Discount & Sale Price Calculator
Find the sale price, work out % off, or combine multiple stacked discounts.
Fuel Cost Calculator
Calculate trip fuel cost in miles/mpg or km/L per 100km, with cost splitting.
Brazil MEI DAS Calculator — Monthly Simples Nacional Payment (2025)
Calcule o DAS mensal do MEI por tipo de atividade — valores fixos 2025.
GPA Calculator
Calculate your GPA — US 4.0, UK Honours, or India 10-point CGPA.
Mexico RFC & CURP Decoder + ISR Net Pay Calculator (2024)
Decode your RFC or CURP and see your take-home pay after ISR — all in your browser.
Malaysia SST Calculator (Sales and Services Tax) 2025
Add or extract Malaysia Sales and Services Tax at 8% — instant result in your browser.
Mexico IVA Calculator (Impuesto al Valor Agregado) 2025
Add or extract Mexico Impuesto al Valor Agregado at 16% — instant result in your browser.
SIP Calculator
Project the future value of a monthly SIP investment.
Hours Between Times Calculator
Duration between two clock times, with break deduction.
Road Trip Cost Calculator
Estimate the fuel cost of a journey and split it between passengers.
EV Charging Cost Calculator
Work out the cost of charging your electric car from any % to any %.
Car Depreciation Calculator
Project a car's resale value year by year using a declining-balance rate.
Grade Calculator
Add your assignments and points to get your overall grade and letter.
Final Grade Needed Calculator
Find the exact score you need on your final to hit your target grade.
Words Per Minute Typing Test
Measure your typing speed in WPM with live accuracy tracking.
UK Degree Classification Calculator
Work out your credit-weighted average and honours classification.
Spain NIF / NIE / DNI Validator
Check the control letter of a Spanish DNI, NIE or NIF instantly.
Poland PESEL Decoder
Decode date of birth, sex and check digit from a Polish PESEL.
South Africa ID Number Decoder
Decode birth date, gender and citizenship from a South African ID.
Chile RUT Validator
Verify a Chilean RUT/RUN verifier digit and get the correct one.
Leap Year Checker
Check if any year is a leap year and see why.
Day of Year Calculator
Find the ordinal day number and ISO week for any date.
Discount Stacking Calculator
Combine multiple discounts and see the true compounded saving.
Germany Steuer-ID Validator (Steuerliche Identifikationsnummer)
Check an 11-digit German Steuer-ID with the official MOD 11,10 check digit.
France NIR / Numéro de Sécurité Sociale Validator
Validate a French social-security number and decode its 13-digit structure.
Sweden Personnummer Decoder & Luhn Validator
Decode a Swedish personnummer — date of birth, gender and Luhn check digit.
Finland HETU Decoder (Henkilötunnus)
Decode a Finnish HETU — date of birth, gender and modulo-31 control character.
Denmark CPR Number Decoder
Decode a Danish CPR (personnummer) — date of birth, gender and century.
Norway Fødselsnummer Decoder
Decode a Norwegian fødselsnummer — date of birth, gender and checksum.
Belgium National Number Decoder
Decode a Belgian Rijksregisternummer — date of birth, gender, checksum.
Pakistan CNIC Validator & Decoder
Check a 13-digit Pakistani CNIC and read its province and gender digit.
Bangladesh NID Validator
Check a 10, 13 or 17-digit Bangladesh NID and read its embedded fields.
Malaysia MyKad Decoder
Decode a 12-digit MyKad — date of birth, place of birth and gender.
Thailand National ID Validator
Validate a 13-digit Thai National ID with its official mod-11 check digit.
China Resident ID Decoder & Validator
Decode an 18-character Chinese ID and verify its ISO 7064 check character.
Vietnam CCCD Decoder
Decode a 12-digit Vietnamese CCCD — province, birth year and gender.
Nigeria NIN Validator — Check Your 11-Digit NIN Format
Validate the format of a Nigerian National Identification Number offline.
Kenya National ID Validator — Check ID Number Format
Validate the format of a Kenyan national ID number offline.
Ghana Card PIN Validator — Check GHA Number Format
Validate the GHA-NNNNNNNNN-N format of a Ghana Card PIN offline.
Tanzania NIDA Number Validator & Decoder
Validate a 20-digit Tanzanian NIDA NIN and decode its date of birth.
Uganda NIN Validator & Decoder — Class, Gender & Birth Year
Validate a 14-character Ugandan NIN and decode its class, gender and birth-year digits.
Saudi Iqama & National ID Validator
Validate a 10-digit Saudi ID or Iqama with the official check-digit algorithm.
Israel Teudat Zehut (ID) Validator
Validate an Israeli Teudat Zehut number with the official checksum.
Morocco CIN / CNI Validator
Check a Moroccan CIN format and read the issuing-bureau region from the prefix.
Jordan National ID Validator
Check a 10-digit Jordanian National Number and read its generation marker.
Argentina CUIT / CUIL Decoder
Verify an Argentine CUIT/CUIL check digit and read its type prefix and DNI.
Colombia Cédula & NIT Validator
Check a Colombian cédula format and compute the NIT modulo-11 check digit.
Peru DNI Validator
Format-check a Peruvian DNI and compute its RENIEC verification digit.
Ecuador Cédula Validator
Validate an Ecuadorian cédula with the official modulo-10 algorithm.
Chile RUT / RUN Checker
Verify a Chilean RUT/RUN verifier digit with the modulo-11 algorithm.
US SSN Format Validator — Check Social Security Number Structure
Validate the structure of a US Social Security Number against SSA rules.
Australia TFN Validator — Tax File Number Checksum
Validate an Australian Tax File Number with the ATO modulus-11 checksum.
New Zealand IRD Number Validator — Check Digit Verification
Validate a New Zealand IRD number with the Inland Revenue modulus-11 check.
India Aadhaar Format Validator — Verhoeff Checksum Check
Validate the format of an Indian Aadhaar number with the Verhoeff checksum.
Chinese Zodiac Finder
Find your Chinese zodiac animal, element and yin-yang from your birth date.
Watts to Kilowatt-Hours (kWh) Calculator
Turn watts and running time into kWh — kWh = (W × hours) ÷ 1000. Free, browser-only.
Data Transfer Cost Calculator
Estimate cloud or CDN egress cost from volume, price per GB and free tier.
Gross to Net Pay Estimator
Estimate take-home pay from gross using your own deduction percentages.
Steps to Distance Calculator
Convert daily steps into kilometres, miles and estimated calories.
Modulo Calculator (Remainder)
Find a mod n — both the truncated and floored remainder conventions.
Work Hours Calculator
Add up a weekly timesheet — daily hours, breaks and optional gross pay.
Rent vs Buy Calculator
Compare the long-term cost of renting versus buying a home.
Scientific Calculator
Evaluate expressions with trig, logs, roots, powers, and factorials.
What Day Was I Born
Find out which day of the week you were born on.
Spain CIF Validator
Check the control character of a Spanish company tax ID (CIF) instantly.
Indonesia NPWP Validator
Check the structure of an Indonesian taxpayer number (NPWP) instantly.
Switzerland AHV Validator
Check the EAN-13 check digit of a Swiss AHV / AVS number instantly.
Greece AMKA Decoder
Decode the birth date and check digit of a Greek AMKA instantly.
Credit Card Payoff Calculator
How long to clear a card — and what the interest costs.
Lease vs Buy Calculator
Compare the true cost of leasing against buying with finance.
Child Height Predictor
Estimate a child's adult height from the parents' heights.
Time Until the Weekend
Live countdown to Saturday — how long until the weekend.
Parallel Resistance Calculator
Total resistance of resistors wired in parallel.
Series Resistance Calculator
Total resistance of resistors wired in series.
Power (Watts) Calculator
Electrical power from voltage, current and resistance.
Work and Power Calculator
Work W = F·d·cos θ and power P = W/t or P = F·v.
Music Interval Calculator
Transpose a frequency by any interval and see ratios in cents.
Video Bitrate Calculator
Work out video file size from bitrate and duration, or the reverse.
Cost-Plus Pricing Calculator
Set a selling price by adding a markup to your unit cost.
Hourly Rate Calculator
Convert an annual salary into an equivalent hourly rate.
Smoking Cost Calculator
See what smoking costs per day, month, year and beyond.
Slope Calculator
Slope, equation and angle of a line through two points.
Distance Between Two Points Calculator
Straight-line distance between two coordinates.
Midpoint Calculator
Find the midpoint between two coordinates.
Quarter Calculator
Find which calendar quarter a date falls in, with start and end dates.
Fiscal Year Calculator
Find the fiscal year for any date — UK, US, Australia and more.
Polynomial Roots Calculator
Find the real and complex roots of quadratic and cubic equations.
Exposure Value (EV) Calculator
Compute EV and EV100 from aperture, shutter and ISO.
F-Stop Calculator
Stops difference and light change between two apertures.
FPS Timecode Calculator
Convert HH:MM:SS:FF timecode to frames and real time.
Bitrate Calculator (Audio + Video)
Find the bitrate needed to fit a target file size.
Zakat Calculator
Work out zakat at 2.5% on wealth above the nisab threshold.
Tithe Calculator
Calculate your tithe from gross or net income at any rate.
Change Maker Calculator
Work out change owed and the fewest notes and coins to give it.
Sweat Rate Calculator
Work out how much fluid you lose during exercise.
Blood Type Inheritance Calculator
Predict a child's possible blood types from both parents.
Period & Cycle Tracker
Predict your next period, ovulation and fertile window.
Body Frame Size Calculator
Small, medium or large frame from height and wrist.
Resting Metabolic Rate Calculator
Estimate your RMR and daily calorie needs.
Semester Weeks Calculator
Count how many weeks a semester or term runs from start to end.
Time Tracker & Timesheet
Start and stop timers per project, see daily and weekly totals, export a CSV timesheet.
Rent vs Buy Comparison Calculator
Full multi-year comparison with breakeven point and net-worth chart.
Exam Time Per Question Calculator
Pace your exam — how long to spend on each question.
Group Gift Splitter
Split a group gift fairly — down to the last cent.
Road Trip Time Estimator
How long will the drive really take — with rest stops added.
Parking Cost Calculator
Find the cheapest way to pay — hourly, daily cap or weekly pass.
Grade Tracker
Track every course, weight each assignment and see the score you need on the final.
Subscription Tracker
Track every subscription, see your true monthly and yearly spend, and never miss a renewal.
Tax Bracket Visualizer
See how a progressive tax schedule splits your income — marginal vs effective, on a stacked bar.
Cap Rate Calculator
Capitalization rate from NOI and property value.
Cash-on-Cash Return Calculator
Annual cash flow as a percentage of cash invested.
Inventory Turnover Calculator
How many times you sell through stock per year.
Darts Checkout Calculator
Find a 1–3 dart finish for any score from 2 to 170.
Light Travel Time Calculator
How long light takes to cross any distance in space.
Pomodoro Estimator
Estimate how long a set of pomodoros will really take.
Cycling Power Estimator
Estimate the watts needed to ride at a given speed.
Screen Time Cost Calculator
See how many hours and how much your daily screen time really adds up to.
Travel Itinerary Planner
Plan trips day by day with timed activities, costs and a printable PDF.
Weekly Schedule Maker
Build a colour-coded weekly timetable and export it to PDF.
Bill Reminder Tracker
Track every recurring bill, see what is due, and never miss a payment.
Timesheet Maker
Log daily hours per project, see totals and billable amounts, export to CSV.
Subscription Cost Tracker
Track every subscription, see your true monthly and yearly spend, and never miss a renewal.
Portfolio Rebalancer
Turn target allocations into exact buy and sell amounts.
Project Timeline Calculator
Turn task estimates in working days into real start and finish dates.
Final Grade Calculator
Work out the exact score you need on your final exam to hit your target grade.
Semester GPA Planner
Track every semester, see your cumulative 4.0 GPA, and reverse-solve a target.
Half-Life Calculator
Solve radioactive decay for remaining amount, time or half-life — with a decay chart.
Density Calculator
ρ = m ÷ V — solve for density, mass, or volume with full unit conversion
Force Calculator (F = ma)
Newton's second law — solve for force, mass, or acceleration with full unit handling.
Dew Point Calculator
Temperature + relative humidity → dew point, comfort rating, wet-bulb temp.
Heat Index Calculator
Temperature + humidity → feels-like heat index with risk category, in °C and °F.
Wind Chill Calculator
Find the real feels-like temperature: air temp + wind speed → wind chill with frostbite risk.
Japan Consumption Tax Calculator
Add or remove Japan's 10% standard or 8% reduced consumption tax instantly.
Ten-Pin Bowling Score Calculator
Enter each roll and watch the official scorecard fill in automatically.
Cricket Net Run Rate (NRR) Calculator
Calculate your tournament NRR correctly — with the bowled-out rule applied.
Cricket Run Rate Calculator
Instantly calculate CRR and RRR — current and required run rates for any match situation.
Darts Checkout Calculator
Find every valid finish for any score from 2 to 170.
Golf Handicap Calculator
Score differentials and Handicap Index using the World Handicap System (WHS).
Race Time Predictor
Predict finish times across every distance from one known race result.
Run/Walk Interval Calculator
Plan your run-walk intervals, find your effective pace and finish time.
Resting Metabolic Rate Calculator
Five peer-reviewed equations, macro splits, formula working — all in your browser.
Watts per kg Calculator
Find your cycling W/kg and Coggan category in seconds.
Body Frame Size Calculator
Determine your skeletal frame size and ideal body weight range instantly.
Doubling Time Calculator
How long until your money, population, or investment doubles?
Drone Flight Time Calculator
Physics-based flight time from battery, mass, rotors and altitude.
Country Plug Type Finder
Instantly look up the plug type, voltage and frequency for any country.
Name Day Finder
Find the name day for any first name — or discover which names are celebrated on any date.
What Time Is It In…?
Instant live clock for any city or country — runs entirely in your browser.
Zodiac Sign Calculator
Find your Western zodiac sign, element, quality and ruling planet from your birthday.
Chinese Zodiac Calculator
Find your animal sign, element, Yin/Yang polarity and lucky attributes from your birth date.
Country Dialing Code Lookup
Find any country dialing code instantly and convert local numbers to international format.
Country Driving Side Lookup
Instantly check whether any country drives on the left or right side of the road.
Mixed Number Calculator
Add, subtract, multiply and divide mixed numbers with full working shown.
Time Zone Difference Calculator
Compare the current time (or any custom time) across multiple time zones instantly.