Average return calculator (arithmetic and geometric)

Enter each period’s return (or the successive values of an investment). The geometric mean tells what you really earned per period; the arithmetic mean overstates it as soon as returns vary.

Average return calculator (arithmetic and geometric)

I am entering
Returns in % (e.g. 10; -5; 20) or values (e.g. 100; 110; 104.5).

Result

6.61%Geometric average return per period

Arithmetic average return per period
7%
Annualized return (compound)
6.61%
Total cumulative return
29.16%
Standard deviation of returns
10.61%
Number of periods
4

Average return calculator (arithmetic and geometric)

Inputs

I am entering
Returns in %
List
10; -5; 20; 3
Length of one period
One year

How it is calculated

Arithmetic = sum of returns ÷ number of periods (plain average, no compounding).

Result

Geometric average return per period

6.61%
Arithmetic average return per period
7%
Annualized return (compound)
6.61%
Total cumulative return
29.16%

How it is calculated

  1. Arithmetic = sum of returns ÷ number of periods (plain average, no compounding).
  2. Geometric = (Π (1 + r))^(1 ÷ n) − 1: the steady return that gives the same end result.
  3. Annualized = (1 + geometric)^(periods per year) − 1. Total = Π (1 + r) − 1.
  4. With values, each return = value ÷ previous value − 1.

Example

Yearly returns of 10%, −5%, 20% and 3%: geometric mean 6.61% versus 7.00% arithmetic, 29.16% in total, standard deviation 10.61% over 4 periods.

Good to know

  • Time-weighted return: money added or taken out along the way is not counted (this is not a money-weighted return).
  • Past performance does not predict future performance.

Frequently asked questions

What is this tool used for?

Enter each period’s return (or the successive values of an investment). The geometric mean tells what you really earned per period; the arithmetic mean overstates it as soon as returns vary.

How is the result calculated?

Arithmetic = sum of returns ÷ number of periods (plain average, no compounding).

What should I check before using the result?

Time-weighted return: money added or taken out along the way is not counted (this is not a money-weighted return).

Updated October 10, 2026

Indicative result. For an important decision, check with a professional.