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What is the Rule of 72 Calculator?

The Rule of 72 is a simple formula used to estimate the number of years required to double the invested money at a given annual fixed interest rate.

How to Use This Calculator

1

Enter the annual interest rate (percentage).

2

Click 'Calculate' to see approximately how many years it will take to double your investment.

Example Calculation

7% annual return

With a 7% annual return, it will take approximately 10.3 years (72 / 7) to double your money.

Frequently Asked Questions

Pro Tips

  • Use this rule for quick mental math to evaluate investments.
  • Remember that higher returns usually come with higher risk.
  • It works for debt too – showing how fast debt can double at high rates.