Rule of 72 Calculator
The simplest way to estimate investment doubling time.
Estimated Doubling Time
9.0
YearsWhat is Rule of 72?
The Rule of 72 is a simple way to determine how long an investment will take to double given a fixed annual rate of interest. By dividing 72 by the annual rate of return, investors can get a rough estimate of how many years it will take for the initial investment to duplicate itself.
How Accurate is it?
For rates of return between 6% and 10%, the rule is remarkably accurate. As rates get extremely high or low, the margin of error increases slightly, but it remains one of the most useful mental shortcuts in finance for evaluating growth potential.
Doubling Time Comparison
4%
18 Years
6%
12 Years
10%
7.2 Years
12%
6 Years