Compound Interest Calculator

Enter starting balance, monthly contribution, expected annual return, years, and compounding frequency. The tool returns estimated final value, total contributions, and estimated growth.

1. Enter the starting amount.
2. Add the monthly contribution (zero is fine).
3. Set the expected annual return percentage and the time horizon in years.
4. Pick a compounding frequency.
5. Read the projected final value, total contributions, and growth.

Future Value = Principal × (1 + r/n)^(n × Years)
With recurring contributions, future value adds the growth of each periodic deposit.

$5,000 start, $200/mo, 7% annual return, monthly compounding, 20 years → about $135,500 final value, $53,000 contributed, $82,500 estimated growth.

• Assuming a flat optimistic return forever. Real returns are noisy.
• Ignoring taxes, fees, and inflation. They quietly trim the curve.
• Comparing the result to actual market history without that context.