# Calculating Rule of Seventy Two

# Rule of 72 Calculator

An online rule 72 calculator tells you, how long it will take to double an investment.

Detailed Output

## Rule of 72 Formula

The rule of 72 is a quick approximation of how long it will take to double an investment.

R x T = 72

Where,

T = Number of Periods, R = Interest Rate as a percentage

Interest Rate required to double your investment R = 72 / T

Number of Periods to double your investment T = 72 / R