Rule of 72 Calculator
A quick mental-maths rule: divide 72 by the annual return to estimate years needed to double money.
- Free
- No signup
- Private: runs in your browser
- Works on mobile
Results are estimates for information only and are not financial, tax or legal advice. Rates and rules change, so confirm with the official source or a qualified professional.
Rule of 72 Calculator tool
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Example
With the default values shown in the tool, the results look like this:
- Years to double (Rule of 72)
- 8 years
- Exact
- 8.04 years
How to use Rule of 72 Calculator
- Enter your values in the fields above.
- The result updates instantly as you type or change an option.
- Copy the result or note it down. Nothing is saved on our servers.
Why use DocConvertPRO?
- Free to use with no signup or watermark.
- Everything runs in your browser. Your input is not uploaded.
- Works on phones, tablets and computers.
- Made for Indian users: rupees, lakh/crore formats and local use cases.
About this tool
Years to double ≈ 72 ÷ rate. The exact value uses ln(2) ÷ ln(1 + rate).
Frequently asked questions
How accurate is the rule?
Very close for rates between 6% and 10%.
Can I use it for inflation?
Yes. It shows how fast prices double.
Is it a guarantee?
No.