# The Rule of 72

How long will it take for your money to double? Are you keeping up with inflation?

## How Long Will It Take For Your Money To Double?

The "Rule of 72" estimates how long it will take an investment to double your money at a given interest rate.

### Rule of 72 Calculator

I added a formula for your current age so you can see how many approximate double periods you'll experience in your lifetime. This way you account for inflation to see how much money will really be required for financial independence.

Alternatively, you can calculate what interest rate you need to double your investment within a certain time period. For example, if you wanted to double your money in 5 years, divide 72 by 5 and you'll need to earn 14.4% interest annually on your investment for 5 years: 14.4 × 5 = 72

### Rule of 72 Formula

The Rule of 72 is a simple way to estimate a compound interest calculation for doubling an investment. The formula is interest rate multiplied by the number of time periods = 72:

R * t = 72

• R = interest rate per period as a percentage
• t = number of periods

Interest Rate: The annual nominal interest rate of your investment in percent.
Time Period in Years: The number of years the money will remain invested.
Compounding: This calculator assumes the frequency of compounding is once per period and that accrued interest is compounded over time.