Compound Interest Calculator

See how much you could have by combining an initial deposit with regular contributions and compound interest. Enter your numbers and optional inflation for real purchasing power.

Inputs

How often you add the contribution (monthly or once per year).

Assumed growth rate, compounded monthly.

Results

Ending balance$32,703.47
Total you put in$25,000
Interest / growth earned$7,703.47

Balance over time

Projected balance at your entered rate (nominal dollars). Uses the same assumptions as the results above.

How it works

Contributions are added at the end of each period (month or year). Each month your balance grows by (annual rate ÷ 12), then we add that period's contribution. We compound monthly.

Total you put in = initial deposit + all recurring contributions over the time horizon. Interest / growth earned = ending balance minus total you put in.

If you set an inflation rate, we also show the ending balance (and balance at 10 and 20 years when applicable) in today's dollars—adjusted for inflation so you can compare purchasing power. The chart shows nominal dollars only.

FAQ

Are these calculators financial advice?
No. All tools are for educational and estimation purposes only. Always do your own research and consider consulting a financial advisor.
Do you store my data?
No. All calculations run in your browser. We do not collect or store your inputs.
What interest rate should I use?
For long-term savings, 3–7% is often used as a rough estimate. This is only an estimate; actual returns will vary. The calculator assumes the rate is constant over time.
How is this different from the Millionaire Calculator?
The Millionaire Calculator answers "when do I reach $100k, $500k, $1M?" and shows years until each milestone. This calculator answers "how much will I have after N years?"—you choose the time horizon and get an ending balance and growth breakdown.

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Calculators are for education and estimation only. Not financial advice.