You can find the answer with the rule of 72. Here’s how it works. Compounding interest is the interest you earn on a growing amount of money.) To find out how long it will take your money to double, take the number 72 and divide it by the interest rate earned. This will give you the number of years it will take to double your money. For instance, If you can earn 6% it will take 12 years to double. This is because 72 divided by 6 equals 12.If you want your money to double in 9 years you would have to earn 8%,Because 72 divided by 9 equals 8.This rule gives you a good rule of thumb to find out what interest rate you need to double your money in the time you want, and it’s easy to calculate. How fast do you want to double your money? Give us a call and we’ll help you get there.