Rule 72 Time to Double Calculator
This calculator uses Rule 72 to estimate how long it will take to double an investment at a given interest rate. Input the annual interest rate, and the calculator will show you the approximate number of years required to achieve your goal.
Calculate the Time to Double Your Investment Using Rule 72
Rule 70 Formula for Time to Double
$$text{Time to Double} = frac{72}{r}$$
Where:
- r – Annual interest rate (as a percentage)
The Rule of 72 is an easy-to-use rule of thumb for estimating how long it takes for an investment to double, given a fixed interest rate. It is widely applied in personal finance, investing, and savings planning. This rule assumes that interest is compounded periodically (monthly, quarterly, etc.). While it provides a good approximation, the actual time to double will depend on the frequency of compounding.