Compound Interest Calculator

See how much your money can grow — and discover how much of your final balance comes from interest rather than what you actually put in.

Investment Details
$
How much you're starting with today (can be $0)
$
Amount you add each month going forward (can be $0)

%
S&P 500 historical avg ≈ 7% (inflation-adjusted)
years
How long you plan to let the money grow
How often interest is calculated and added to your balance
Final Balance
—
after — years
Total Contributed
—
what you personally put in
Interest Earned
—
money the market added
Growth Multiple
—
times your money grew
Growth Over Time
Your Contributions Interest Earned
Year-by-Year Breakdown
Year Starting Balance Annual Contribution Interest Earned Ending Balance Total Contributed Total Interest

* Results are estimates for educational purposes only. This calculator assumes a fixed, consistent rate of return and does not account for taxes, investment fees, inflation, or market volatility. Past market performance does not guarantee future results. Consult a licensed financial advisor before making investment decisions.