Compound Interest Calculator

Enter a starting amount, monthly contribution, annual return and years to see your future balance.

How it works

Interest is added every month and then earns interest itself. Over long periods, growth can exceed what you put in.

Results assume a constant return; real investments go up and down.

Frequently asked questions

How much will $500 a month grow in 20 years?
At 7% a year, about $260,000, of which $120,000 is your contributions.
What is the rule of 72?
Divide 72 by the annual rate to estimate how many years it takes to double your money.
Are taxes included?
Only if you enter a tax rate on gains.