Rule of 72 (doubling time)
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By the rule of 728 yr
Exact8.04 yr
Worked example
Given: Annual return = 9 %
Result: By the rule of 72 = 8 yr; Exact = 8.04 yr
How it is calculated
1. Enter the values you know. 2. The calculator converts them to base units and applies the formula. 3. The result is shown in the unit you choose.
Frequently asked questions
How do I calculate it?
Given: Annual return = 9 %. Result: By the rule of 72 = 8 yr; Exact = 8.04 yr.
Is the calculator free and private?
Yes. It is free, needs no sign-up and runs in your browser — the numbers you type stay on your device.