How is CAGR calculated?

CAGR is the ending value divided by the beginning value, raised to the power of one over the number of years, then minus one — written as a percentage per year. In symbols, CAGR = (Ending ÷ Beginning)^(1 ÷ years) − 1.

How is CAGR different from a simple average return?

A simple average just adds the yearly returns and divides by the number of years, which ignores compounding and the order of gains and losses. CAGR is the single steady rate that actually links the start value to the end value, so it is always less than or equal to the average whenever returns are volatile. That makes CAGR the fairer figure for comparing investments over different time spans.

Can CAGR be negative?

Yes. If the ending value is lower than the beginning value, the CAGR is negative and represents an average annual loss rather than a gain. This calculator shows the figure in red and still reports the total return and growth multiple so you can see the full picture.

What is the contribution-adjusted CAGR for?

Plain CAGR assumes one lump sum grows untouched. If you also added money each year, that fresh cash inflates the ending value and makes the plain CAGR overstate how well your picks performed. Enter an amount in the optional added-per-year field and the tool solves for the annual rate that compounds your starting balance plus those yearly deposits up to the ending value — a money-weighted estimate closer to a true internal rate of return.

How do I convert CAGR back into total return?

Total return equals (1 + CAGR)^years − 1. For example a 14.59% CAGR over 7 years gives (1.1459)^7 − 1 ≈ 160%, matching a balance that grew from 10,000 to 26,000. The growth multiple shown by the tool, 2.6x here, is simply 1 plus the total return.

How long does it take to double at a given CAGR?

The exact answer is ln(2) ÷ ln(1 + CAGR) years, which the calculator reports as years-to-double. The well-known Rule of 72 (72 ÷ growth percent) is a quick mental approximation of the same figure and is accurate to within a few percent for rates between roughly 5% and 15%.

Is my data uploaded anywhere?

No. Every calculation happens entirely in your browser, your figures are only stored locally so they survive a refresh, and nothing you enter is ever sent to a server.

CAGR Calculator — Gera Tools

CAGR — compound annual growth rate — is the single yearly rate that would take an investment from its starting value to its ending value if it grew steadily every year. It is the standard, like-for-like way to compare funds, stocks, crypto, property or a business metric such as revenue across different time spans, because it strips out the noise of lumpy year-to-year returns and reports one clean number.

This calculator turns three inputs — a beginning value, an ending value and a number of years — into the CAGR, and goes further than a bare percentage. It also shows the total return over the whole period, the growth multiple (how many times your money grew), the years-to-double at that rate, and an optional contribution-adjusted rate for when you also drip-fed money in. The full working is printed step by step, and a chart draws the idealised smooth-growth curve so you can see what steady compounding at your rate looks like. Pick from several currencies or choose a neutral no-symbol mode — every input is a number you type, so there are no live market or exchange-rate lookups anywhere.

How it works

The calculator applies the CAGR formula, where the growth multiple is the ending value divided by the beginning value:

CAGR = (Ending ÷ Beginning)^(1 ÷ years) − 1

That result is shown as a percentage per year. Total return is the simpler ratio (Ending ÷ Beginning − 1) × 100, and years-to-double comes from ln(2) ÷ ln(1 + CAGR). CAGR is always lower than a naive average of yearly returns whenever those returns swing around, because it bakes in compounding and the order of gains and losses.

When you fill in the optional added-per-year field, the tool can no longer use a closed-form formula, so it solves numerically: it finds — by bisection — the annual rate that grows your starting balance plus each year-end deposit up to exactly the ending value. That contribution-adjusted figure is a money-weighted estimate and is usually a fairer measure of how your own choices performed than the plain CAGR.

Worked example

Suppose a portfolio grew from 10,000 to 26,000 over 7 years with no money added or removed:

Growth multiple = 26,000 ÷ 10,000 = 2.6
CAGR = 2.6^(1 ÷ 7) − 1 = 2.6^0.142857 − 1 ≈ 0.1459
CAGR ≈ +14.59% per year
Total return = +160%, and it would double about every 5.1 years

Now suppose you also added 2,000 each year over those 7 years. That extra cash helped reach 26,000, so the rate your original picks actually earned is lower — the contribution-adjusted CAGR drops to roughly 8%, a far more honest read on performance.

Beginning	Ending	Years	CAGR
10,000	20,000	10	7.18%
10,000	26,000	7	14.59%
10,000	18,000	5	12.47%
5,000	4,000	3	−7.17%

Formula note: raising a ratio to a fractional power is only defined for a positive beginning value and a non-zero number of years, which is why the tool asks for valid inputs before it computes. Plain CAGR deliberately ignores interim deposits and withdrawals — for cash flows in and out over time, use the contribution-adjusted mode here or a full internal rate of return (IRR).

Every figure is calculated in your browser, so your numbers stay completely private.