What is Rule of 72 Calculator?
Divide 72 by the annual return to get roughly how many years it takes for money to double with compound interest. Shows the rule-of-72 value alongside the exact logarithmic calculation, plus the time to triple (rule of 114) and quadruple (rule of 144), and how long inflation takes to halve your money's value.
How to use
- 1
Choose years to double or required return.
- 2
Enter a return or a period.
- 3
Compare the rule-of-72 value with the exact value.
Use cases
Comparing investments
Compare how long 4% and 8% products take to double.
Feeling inflation
See when your money loses half its value at 3% inflation a year.
FAQ
Is the information I enter saved?+
No. All calculations happen in your browser and nothing is stored or sent anywhere.