Planning
Rule of 72
A back-of-the-envelope estimate: divide 72 by an annual return to approximate the number of years your money takes to double. We also show the exact figure for comparison.
Rule of 72 (approx)
10.3 yrs
Exact doubling time
10.24 yrs
Reference table
2%
36.0 yrs35.00 yrs
3%
24.0 yrs23.45 yrs
4%
18.0 yrs17.67 yrs
5%
14.4 yrs14.21 yrs
6%
12.0 yrs11.90 yrs
7%
10.3 yrs10.24 yrs
8%
9.0 yrs9.01 yrs
9%
8.0 yrs8.04 yrs
10%
7.2 yrs7.27 yrs
12%
6.0 yrs6.12 yrs
15%
4.8 yrs4.96 yrs
| Return | Rule of 72 | Exact |
|---|---|---|
| 2% | 36.0 yrs | 35.00 yrs |
| 3% | 24.0 yrs | 23.45 yrs |
| 4% | 18.0 yrs | 17.67 yrs |
| 5% | 14.4 yrs | 14.21 yrs |
| 6% | 12.0 yrs | 11.90 yrs |
| 7% | 10.3 yrs | 10.24 yrs |
| 8% | 9.0 yrs | 9.01 yrs |
| 9% | 8.0 yrs | 8.04 yrs |
| 10% | 7.2 yrs | 7.27 yrs |
| 12% | 6.0 yrs | 6.12 yrs |
| 15% | 4.8 yrs | 4.96 yrs |