Rule of 72

he Rule of 72 is a simple way to estimate how long it will take for an investment to double in value, given a fixed annual rate of return.

How it works:

  • You divide the number 72 by the annual interest rate (in percentage) to get an approximate number of years it will take for your money to double.

  • It’s a quick mental math shortcut for investors to understand growth over time without complex calculations.

  • It works best for interest rates between about 6% and 10%.