Compound Interest Calculator
Watch your money grow — starting balance plus monthly contributions, compounding over time. The earlier you start, the harder it works.
Future Value
$0
Total Contributions$0
Interest Earned$0
Money Multiplied—
Doubling Time (Rule of 72)—
Contributions are added at the start of each month and grow at the effective rate of your chosen compounding frequency. At 7% (the stock market's rough long-term real average), money doubles about every 10 years — which is why starting at 25 instead of 35 can roughly double your final balance. Estimates only; investment returns vary.