Compound Interest Calculator

Compare up to three scenarios side by side — adjust any of them and press Calculate to update the chart and table below.

How this works

Compound interest is calculated as A = P(1 + r/n)nt, where P is your principal, r is the annual rate as a decimal, n is how many times per year interest compounds, and t is time in years. Extra contributions are added at the end of each contribution period, so they start earning interest from the following period, not immediately. Add up to two more scenarios to compare different rates, contributions, or time horizons side by side.