Rule of 72 Calculator

There are 2 things calculated.

Interest rate required to double the investment : R = 72 / T

Number of periods to double the investment : T = 72 / R
Here,
T = Number of Period.
R – Rate of Interest.

Example,
If you want to double your investment of in 7 years. How much interest you must earn in a year ?

R = 72 / T
R = 72 / 7 = 10.2857 %

You will have to earn 10.29% interest to double your investment in 7 Years.

If you earn 5% interest on your investment every year. How many years it will take to double your investment ?
T = 72 / R
T = 72 / 5 = 14.4 Years

It will take 14.4 years to double your investment with 5% interest.