How do you calculate a doubling interest rate?

For simple interest, you’d simply divide 1 by the interest rate expressed as a decimal. If you had $100 with a 10 percent simple interest rate with no compounding, you’d divide 1 by 0.1, yielding a doubling rate of 10 years. For continuous compounding interest, you’ll get more accurate results by using 69.3 instead of 72.

How do you calculate a doubling time?

The simple calculation is dividing 72 by the annual interest rate. The Rule of 72 gives an estimation of the doubling time for an investment. It is a fairly accurate measurement, and more so when using lower interest rates rather than higher ones. It is used for situations involving compound interest.

How do you Double Your Money in a year?

Instead of dividing 72 by the rate of return, divide by the number of years you hope it takes to double your money. For example, if you want to double your money in eight years, divide 72 by eight. This tells you that you need an average annual return of 9% to double your money in that time.