What is the Rule of 72?
The Rule of 72 Calculator is a legendary mental-math shortcut used in finance to estimate exactly how many years it will take for an investment to double in value at a given fixed annual rate of return.
The Formula
Years to Double = 72 / Annual Interest Rate
For example, if you invest in an FD offering 7% p.a., it will take approximately (72 / 7) = 10.28 years to double your money. If you invest in an equity fund offering 12%, it doubles in just 6 years!