About Compound Interest Calculator

Compound Interest Calculator shows how money grows when returns earn returns. Enter a starting amount, monthly contribution, expected annual return, and time horizon, then see your final balance, total interest earned, and a year-by-year growth chart instantly.

See compounding, not just totals

The growth chart shows the classic compounding curve: amber is the money you put in, green is what it becomes. A breakdown splits your final balance into starting amount, contributions, and interest earned, with your overall growth multiple.

Flexible compounding

Choose daily, monthly, quarterly, or annual compounding, and toggle the year-by-year table to see contributions, interest, and balance for every year.

Private and free

Every calculation runs locally in your browser. Nothing you enter is uploaded, stored, or sent anywhere. No sign-up, nothing to install. For details on the cookies used by advertising, see our Privacy Policy.

Important disclaimer

This calculator is for general informational and educational purposes only. It does not provide, and must not be relied on as, investment advice, tax advice, legal advice, or financial advice.

• Estimates only. Results assume a constant rate of return with no taxes, fees, or inflation. Real investment returns vary year to year and can be negative.
• Tax rules change. Past performance never guarantees future results. No projection here is a prediction of what any investment will actually do.
• State and local simplifications. Taxes and fees matter. Investment gains may be taxable and funds charge fees; both reduce real-world results and are not modeled here.
• No professional relationship. Using this site does not create any advisor–client, accountant–client, or attorney–client relationship.
• No liability. We accept no liability for decisions made or actions taken based on this tool's output.

For real investment decisions (retirement planning, choosing funds, asset allocation), consult a qualified, licensed financial advisor.