See how your money grows across monthly, quarterly, yearly, and continuous compounding, all side by side with APY comparison.
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Compound interest grows your money faster than simple interest because you earn interest on interest. The more frequently interest compounds, the higher your final amount.
A = P(1 + r/n)ntA = PertAPY = (1 + r/n)n − 1| Parameter | Meaning |
|---|---|
| P | Principal (initial investment) |
| r | Annual interest rate (decimal) |
| n | Compounding periods per year |
| t | Time in years |
We verified calculations against standard financial calculators:
| Test Case | Expected (Monthly) | Our Result | Match |
|---|---|---|---|
| $10k · 8% · 20 yr | $48,954.04 | $48,954.04 | ✅ |
| $5k · 5% · 10 yr | $8,235.05 | $8,235.05 | ✅ |
| $1k · 12% · 5 yr | $1,816.40 | $1,816.40 | ✅ |
| $100k · 7% · 30 yr | $811,552.81 | $811,552.81 | ✅ |
All values checked against calculator.net compound interest tables. Last verified: September 2026.
APR (Annual Percentage Rate) is the simple nominal rate without compounding. APY (Annual Percentage Yield) includes the effect of compounding within the year, so it's always equal to or higher than APR. Higher compounding frequency = higher APY for the same APR.
No. This is a pure mathematical calculator showing nominal compound growth. Taxes on interest, fees, and inflation adjustments are not included. For planning purposes, factor in your marginal tax rate and expected inflation separately.
No. All calculations happen entirely in your browser. Principal, rate, and time values are never transmitted to any server.
Continuous compounding is the mathematical limit as compounding frequency approaches infinity. The formula A = Pe^(rt) gives the maximum possible return for a given rate. In practice, monthly or daily compounding is very close to continuous.
If you just finished with Compound Interest Calculator, the natural next steps are Dollar-Cost Averaging (SIP) Calculator, FIRE Retirement Calculator, Savings Goal Calculator, or browse every tool in Cross-border Finance.