Compound Interest Calculator
See how your money grows with compounding across any frequency and term.
Your investment
Optional — set to $0 for a one-off deposit
Future value after 10 years
$20,097
2.01× your total contributions
- Contributions$10,000
- Interest earned$10,097
- Total contributions
- $10,000
- Interest earned
- $10,097
- Future value
- $20,097
- Interest share
- 50%
Growth over 10 years
Watch interest compound on top of your contributions year after year.
Yearly breakdown
| Year | Contributions | Interest | Balance |
|---|---|---|---|
| 1 | $10,000 | $723 | $10,723 |
| 2 | $10,000 | $1,498 | $11,498 |
| 3 | $10,000 | $2,329 | $12,329 |
| 4 | $10,000 | $3,221 | $13,221 |
| 5 | $10,000 | $4,176 | $14,176 |
| 6 | $10,000 | $5,201 | $15,201 |
| 7 | $10,000 | $6,300 | $16,300 |
| 8 | $10,000 | $7,478 | $17,478 |
| 9 | $10,000 | $8,742 | $18,742 |
| 10 | $10,000 | $10,097 | $20,097 |
About the Compound Interest Calculator
Compound interest is interest earned on both your original money and the interest it has already earned. That snowball effect is why Albert Einstein reportedly called it the most powerful force in finance — and why starting early matters so much. This calculator shows exactly how an initial deposit, plus optional regular contributions, grows over time at a given rate and compounding frequency.
Two settings make compounding more powerful: a higher frequency and a longer time horizon. Interest that compounds daily grows slightly faster than interest compounded annually, because earnings start earning sooner. And because growth is exponential, the final years contribute far more than the first — a balance can double in its last decade alone.
Use the monthly contribution field to model regular investing (like a SIP or 401(k)), and the frequency selector to match how your account actually compounds. The chart and table break down how much of your future value comes from contributions versus interest earned.
Frequently asked questions
What is compound interest?
Compound interest is interest calculated on your initial principal and on the accumulated interest from previous periods. Unlike simple interest (which is only ever calculated on the principal), compounding causes your balance to grow at an accelerating rate.
How does compounding frequency affect growth?
The more often interest compounds, the faster your balance grows, because earned interest starts earning interest sooner. Daily compounding edges out monthly, which beats annual — though at typical rates the difference is modest compared with the rate itself and the time invested.
What's the difference between this and a simple interest calculator?
Simple interest pays a flat amount each period based only on the principal. Compound interest reinvests each period's interest so future interest is calculated on a larger balance — which is how most savings and investment accounts actually work.
Does adding monthly contributions make a big difference?
A large one. Regular contributions are themselves compounded over time, so steady monthly investing often ends up contributing more to your final balance than the starting deposit — especially over long horizons.
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