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Compound Interest Calculator

See the power of compound interest — the 8th wonder of the world

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The Rule of 72

Divide 72 by your annual return rate to find how many years it takes to double your money. At 8%: 72/8 = 9 years. At 12%: 6 years. At 4%: 18 years.

FAQ

How does compound interest work?

Compound interest is interest earned on both your original principal AND your previously earned interest. Over time, this creates exponential growth — your money earns money, which earns more money.

How often is interest compounded?

This calculator compounds monthly, which is standard for most investments. Daily compounding produces slightly more (about 0.1-0.2% annually) but the difference is minimal.

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