Compound Interest Calculator

See how savings grow when interest earns interest. Results update as you type.

Initial deposit

Monthly contribution

Annual interest rate (%)

Years

Compound frequency

Future value

$0.00

Growth over time

How this calculator works

c_howto

Results are estimates for education only and are not financial advice. Assumes a constant rate and contributions at the end of each compounding period.

Why does compounding matter so much?

With simple interest you earn only on your deposits. With compound interest you also earn on past interest, so growth speeds up over time. That is why starting early usually beats saving more later.