Rule of 72 Calculator

Enter an annual return rate to compare the Rule of 72 shortcut with exact annual-compounding doubling time.

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Annual return (%)

Rule of 72 estimate

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ApproximationThe Rule of 72 is a shortcut, not an exact compounding identity. Exact annual-compounding time is shown for comparison.

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How to use this Rule of 72 Calculator

Enter an annual percentage return to estimate doubling time with 72 divided by the percentage rate. The page also shows exact annual-compounding time for comparison.

What the result means

Enter an annual return rate to compare the Rule of 72 shortcut with exact annual-compounding doubling time.

Rule of 72 is an approximation

The page compares 72/r with exact constant annual-compounding doubling time instead of presenting the shortcut as exact.

Planning scope

This calculator is a deterministic planning aid based only on the values you enter. It does not supply current tax rates, market returns, employment-law classifications, individualized investment advice, or product recommendations. Verify real-world rates, rules, fees, and timing separately.