Home & DIY
132 free home & diy tools in the Calculators & Converters collection — every one runs in your browser with no signup and no uploads. Page 1 of 2.
3D Print Total Cost Per Gram
Factor electricity, machine depreciation, and failures into true print cost
3D Print Scale Factor Calculator
Find the scale percentage to resize a model to exact dimensions
3D Print Thread Sizing Chart
Find the correct hole diameter for printed internal threads (ISO, UNC, UNF)
Hot Water Boiler Output & Radiation Calculator
Match boiler net output to connected fin-tube baseboard and cast-iron EDR radiation.
Brick & Block Count Calculator
Estimate bricks or blocks required for any wall area with mortar joint
Room BTU Calculator
Size a window AC, mini-split or portable unit for a room with the ENERGY STAR method
Candle Wax & Fragrance Calculator
Calculate wax and fragrance oil amounts for any candle vessel
HVAC CFM Airflow Calculator
Calculate required supply-air CFM from a room's heat load and supply-air temperature difference
Composite Deck Material Calculator
Estimate lineal feet, boards, and fasteners for a composite deck
Concrete Anchor Pullout Strength Calculator
Estimate anchor bolt tensile capacity in concrete using ACI 318 concrete breakout
Crochet Gauge & Stitch Count Calculator
Scale any crochet pattern for your actual gauge
Cross Stitch Fabric Count Calculator
Calculate finished size for any cross stitch pattern on any fabric count
Deck Joist Span Calculator
Verify allowable joist span for any lumber size, species, and spacing
Water Heater Recovery Rate Calculator
Calculate recovery time and recovery rate for storage water heaters from element kW or gas BTU/h.
Drain Cleanout Spacing & Location Calculator
Verify IPC cleanout requirements by pipe size and placement for horizontal and building drains.
Drywall Sheet Calculator
Calculate drywall sheets, screws, tape, and mud for any room
Earthwork Swell & Shrinkage Calculator
Convert bank, loose, and compacted soil volumes using swell and shrinkage
Fabric Shrinkage Calculator
Calculate pre-washed fabric yardage needed accounting for shrinkage
Fascia, Soffit & Eave Material Calculator
Estimate fascia board, soffit panel area, and J-channel for any roof perimeter
Floor Joist Span Calculator
Verify allowable floor joist span for lumber size, species, and live load
Floor & Wall Tile Calculator
Estimate tile count, thinset bags, and grout for any room with waste factor
Gas Appliance Total BTU/h Load Calculator
Sum gas appliance BTU/h ratings and verify meter and regulator capacity
Boiler Replacement Sizing Calculator
Size a replacement hot-water boiler from Manual J heat loss or connected radiation.
Generator Fuel Runtime Calculator
Estimate how long a gasoline, diesel, or propane generator runs on a given fuel quantity.
Gravel & Aggregate Volume Calculator
Calculate cubic yards and tons of gravel, crushed stone, or sand for any area
Heat Pump Balance Point Calculator
Find the outdoor temp where heat pump capacity equals building heat loss for backup staging
Heat Pump COP & HSPF Calculator
Calculate heat pump COP from output and power, and estimate seasonal HSPF
Heat Pump Savings Calculator
Compare heat pump vs gas boiler running cost and CO2 savings
Supply Grille/Diffuser Velocity & CFM Calculator
Calculate CFM from neck velocity and grille area, or find velocity from CFM and neck size
Evaporator / Condenser Coil Airside Pressure Drop Calculator
Estimate coil pressure drop in inches WC from face velocity and coil rows
Ductwork Heat Gain / Loss Calculator
Estimate BTU/h heat gain or loss from supply and return ducts in unconditioned spaces.
HVAC Economizer Free-Cooling Hours Calculator
Estimate annual free-cooling hours and energy savings from an air-side economizer
Heat Exchanger NTU-Effectiveness Calculator
Find heat exchanger effectiveness and outlet temperatures with the ε-NTU method.
Makeup Air Unit (MAU) CFM Calculator
Size makeup air CFM to replace exhaust and hold building pressurization
Refrigerant GWP & EPA Section 608 Quantity Calculator
Calculate annual leak rate and the EPA-required repair trigger from system charge weight.
Refrigerant Pressure-Temperature (PT) Chart
Look up saturation temperature from gauge pressure for R-22, R-410A, R-32, R-134a, R-404A, R-407C, R-454B
HVAC Tonnage Calculator
Convert a BTU/h cooling load to tons of refrigeration and size equipment to the nearest half-ton
Hydronic Circulater Pump Selection Calculator
Get system GPM and head loss to select a residential hydronic zone circulator
Knitting Increase/Decrease Spacing Calculator
Evenly space increases or decreases over a run of rows or stitches
Home Insulation Payback Calculator
Calculate payback period and CO2 savings for loft or wall insulation
Knitting Blocking Dimensions Calculator
Calculate wet-blocked dimensions from dry measurements and yarn type
Knitting Gauge Converter & Stitch Calculator
Convert gauge swatches and recalculate stitch counts for any yarn
Knitting Provisional Cast-On Reference
Calculate stitch count and method for any provisional cast-on technique
Knitting Row & Round Counter
Count rows, rounds, and repeats for any knitting project
Knitting Sock Heel Turn Calculator
Calculate short-row heel or flap-and-gusset sock heel math
Masonry Lintel Load Calculator
Find the load on a CMU or brick lintel over an opening using 45-degree arching
Net Metering Payback Period Calculator
Estimate solar payback period and 25-year ROI from net-metering credits and system cost
Off-Grid Load Audit Calculator
Total your daily watt-hours from appliance wattage and runtime for off-grid solar design.
Paint Coverage Calculator
Estimate gallons needed for any room based on coverage and coats
PEX vs Copper Flow Rate Comparison Calculator
Compare pressure drop and flow rate between PEX-A, PEX-B, and Type L copper of the same size.
Pipe Insulation Heat Loss Calculator
Calculate heat loss per linear foot from bare vs insulated hot water or chilled water pipe.
Water Supply Pipe Sizing Calculator (Hunter's Curve / WSFU)
Size water supply pipes from fixture-unit count using Hunter's Curve and an 8 ft/s velocity limit
Plumbing Material Takeoff Calculator
Estimate supply and DWV footage, fittings, and WSFU from fixture counts for bidding.
Pipe Offset / Travel Calculator (Plumbing Isometric)
Calculate pipe cut lengths and travel for 45°, 22.5° and 60° offsets
Plumbing Fitting Angle & Rolling Offset Calculator
Solve rolling offsets for pipe runs moving simultaneously horizontal and vertical.
Plumbing Rough-In Dimensions Reference
Look up standard rough-in heights and offsets for toilets, sinks, tubs, showers, and water heaters.
Pet Pool / Paddling Pool Chemistry Calculator
Calculate chlorine and pH adjustment doses for a small pool
Psychrometric Dew Point & Wet Bulb Calculator
Find dew point, wet-bulb temperature, humidity ratio, and enthalpy from dry-bulb and relative humidity
Radiant Floor Heating BTU Output Calculator
Calculate BTU/h output per square foot from radiant in-floor tubing spacing and water temperature.
Rebar Spacing & Lap Splice Calculator
Find bar spacing and required lap-splice length per ACI 318
Refrigerant Charge (Subcooling Method) Calculator
Verify TXV-system charge from liquid-line subcooling against the manufacturer target
Refrigerant Leak-Check Nitrogen Pressure Calculator
Find the safe dry-nitrogen leak-test pressure for an HVAC system by refrigerant MAWP
Refrigerant Oil Charge Calculator (Line Set Extension)
Calculate extra compressor oil needed when extending line sets beyond factory specification
Residential Mechanical Ventilation Calculator (ASHRAE 62.2)
Calculate whole-house ventilation CFM per ASHRAE 62.2 and IECC 2021
Resin Print Support Angle Guide
Determine safe overhang angles without supports for resin SLA/MSLA prints
Retaining Wall Block Count Calculator
Estimate blocks, deadman count, and drainage stone for any retaining wall
Roof Pitch & Rafter Length Calculator
Calculate rafter length, ridge height, and board count from span and pitch
Roofing Square & Material Calculator
Turn a roof footprint and pitch into squares, shingle bundles, and ridge cap
Wood Shear Wall Capacity Calculator
Look up tabulated unit shear for wood-frame shear walls per AWC SDPWS
Soap Lye (Saponification) Calculator
Calculate NaOH or KOH lye amount for any soap oil recipe
Solar Farm Yield Estimator for Agricultural Land
Estimate annual kWh output and agrivoltaic revenue from solar-plus-agriculture installations
PV Panel Mismatch Loss Calculator
Estimate power loss from mixing panels with different Isc or Voc in a string
Solar Panel Daily/Monthly Output Calculator
Calculate expected kWh output from a PV array by watts, sun hours, and derate.
Solar Panel Payback Calculator
Calculate solar PV break-even, savings, and CO2 offset over 25 years
Off-Grid Solar System Calculator
Size solar panels, batteries, and inverter for any off-grid system
Stair Stringer Calculator
Calculate rise, run, stringer length, and angle for any stair height
Standby Power Waste Calculator
Calculate annual cost and CO2 from devices left on standby
HVAC Static Pressure Drop Calculator
Sum total external static pressure across filter, coil, ducts and grilles for blower selection
Roof Drain & Stormwater Pipe Sizing Calculator
Size roof drains and leader pipes from roof area and design rainfall intensity per IPC 1106.
Superheat Calculator (Fixed-Orifice Systems)
Find suction-line superheat from suction pressure and temperature to set the charge
Commercial Plumbing Fixture Count Calculator (IPC 403)
Find minimum water closets, urinals, and lavatories required for an occupancy type per IPC.
Window Rough Opening Calculator
Convert window or door unit size to the framed rough opening dimensions
Wood Framing Member Count Calculator
Calculate studs, plates, headers, and blocking for walls and openings
Yarn Yardage Estimator
Calculate yarn needed for any knitting or crochet project
Wallpaper Rolls Calculator
Work out how many rolls of wallpaper a room needs, including pattern repeat
Gravel Tonnage Calculator
Convert a driveway or path area and depth into tonnes of gravel or aggregate
Mulch Coverage Calculator
Work out how many bags of mulch, bark or compost a bed needs at a given depth
Decking Board Calculator
Count the decking boards a patio needs, including the expansion gap and waste
Air Conditioner BTU Calculator
Size a room air conditioner in BTU from floor area, sun, occupants and use
Tile Calculator
Work out how many tiles and boxes a wall or floor needs, with waste allowance
Raised Bed Soil Calculator
Work out how much soil or compost fills a raised bed, in litres and bags
Laminate Flooring Calculator
Work out how many packs of laminate or engineered flooring a room needs
Grass Seed Calculator
Work out how much grass seed a lawn needs for sowing or overseeding
Fence Post Calculator
Count the posts, panels and postcrete a fence run needs from its length
Paint Calculator
How much paint to buy for any room — walls, coats and openings.
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.