Rule of 72 Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter your annual return.
- Press Calculate.
How it works
Years to double ≈ 72 ÷ annual return — a quick mental estimate of compound growth.
Worked example
8% return. ≈ 9 years to double.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.