Home › Compound Interest Calculator
Compound Interest Calculator
Project how a balance grows over time with an initial amount, regular monthly contributions, and interest that compounds month after month.
Your numbers
$
$
%
yrs
Future value
$0
Balance after compounding
Total contributions$0
Total interest earned$0
How the compound interest calculator works
Compound interest means the interest you earn is added to your balance, so future interest is calculated on a larger and larger amount. With regular contributions, this snowball effect accelerates over time.
FV = P(1+r)ⁿ + PMT · ((1+r)ⁿ − 1) / r compounded monthly
Frequently asked questions
What makes compounding powerful?+
Because interest earns interest, growth accelerates the longer you stay invested. Time in the market usually matters more than the exact rate.
How is this different from simple interest?+
Simple interest is calculated only on the original amount. Compound interest is calculated on the original amount plus all previously earned interest.