Compound Interest Calculator
Calculate compound interest with monthly, quarterly or annual compounding. See how savings grow over time with a year-by-year breakdown.
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The Power of Compound Interest
Compound interest earns interest on both the principal and previously accumulated interest — often called "interest on interest." Over long periods this creates exponential growth. Einstein reportedly called it the "eighth wonder of the world."
Compounding Frequency Impact
| Frequency | Times/Year | Effect |
|---|---|---|
| Annually | 1 | Baseline |
| Quarterly | 4 | Slightly more growth |
| Monthly | 12 | Common for savings accounts |
| Daily | 365 | Maximises compounding effect |
Formula
A = P × (1 + r/n)^(n×t) where P = principal, r = annual rate, n = compounding periods per year, t = years. With regular contributions M: add M × [((1 + r/n)^(n×t) − 1) / (r/n)] to the result.