Rule of 72
Rule of 72: use annual growth rate. Review the formula, worked example and calculation steps.
Inputs
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Formula & explanation
Approximate doubling years = 72/rate%
Variables & units
- Annual growth rate
- % · minimum 0.000001, maximum 1000000000000
Worked example
At6%, the rule estimates12 years to double.
Assumptions
A rough mental approximation. Use Doubling time for the exact constant-rate discrete model.
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