Rule of 72 Calculator
Quickly estimate how long it takes to double your money.
Time to Double Your Money
0 years
Interest Rate
0%
Doubling Time
0 years
exact calculation
Rule of 72
0 years
approximation
Doubling Time at Different Rates
What is the Rule of 72?
The Rule of 72 is a simple way to estimate how long it takes to double your money at a given interest rate.
72 ÷ Interest Rate = Years to Double
For example, at 8% interest: 72 ÷ 8 = 9 years to double.
The rule is most accurate for rates between 6-10%.