The Rule of 72 is a quick formula to estimate how long it will take for your investment to double at a fixed rate of return:

Formula: 72 ÷ Annual Return (%) = No. of Years to double
Example: At 12% annual returns → 72 ÷ 12 = 6 years

You can also use this formular the other way to find out the annual return required to double your money in specific number of years. For example, if you want to double your money in 10 years, you will need to invest in products that give an annual return of about 7.2% (72 ÷ 10).