What is the Rule of 72?

The Rule of 72 is a shortcut for estimating how long it takes savings or investments to double in value. Divide 72 by the annual growth rate (in percent) to get the approximate number of years.

How accurate is the Rule of 72?

The Rule of 72 is an approximation. It is very accurate for rates between 6% and 10%. For lower or higher rates, the exact compound interest formula gives more precise results.

Can I use this calculator for any growth rate?

Yes. You can enter any annual growth rate or time period, and the calculator will show both the Rule of 72 estimate and the exact result from the compound interest formula.

OPTIMLY Calculators | Rule of 72 Calculator

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