Rule of 72 Calculator
The Rule of 72 estimates how many years it takes to double your money: divide 72 by your annual rate of return.
%
$
Your money doubles in
10.3years
$10,000 grows to $20,000 at 7% a year.
Compare scenarios
How long doubling takes at typical returns for each kind of account.
Savings account · 1%
72.0 years
Bonds · 4%
18.0 years
Stock market · 7%
10.3 years
This calculator is for educational purposes only. The Rule of 72 is an approximation that works best for returns between about 4% and 12%. Actual investment returns vary and past performance does not guarantee future results.