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Rule of 72 Calculator
Free Rule of 72 calculator — rough years to double money using 72 ÷ annual return %.
Last updated 2026-09-18
Years to double (approx)
6.0
Thumb rule, not exact compounding.
How it works
Years to double ≈ 72 / annual percent.
How to use this calculator
- Enter the inputs shown above (amount, rate, tenure, income, or other fields).
- Read the live results — they update as you type.
- Check the formula, worked example, and assumptions on this page before you decide.
Formula
Years to double ≈ 72 / annual percent.
Worked example
At 12%, doubling takes about 6 years in this thumb rule.
Reading the result
Treat the output as a planning figure. Compare it with your sanction letter, payslip, or GST invoice rather than treating it as a filing or a loan offer.
See also: calculation methodology and disclaimer.
Frequently asked questions
It is a shortcut, closer at mid-single to low-double-digit rates. Use compound interest for an exact doubling time.
Assumptions and limits
- This is a planning estimate. Your lender, employer, or tax officer may use different inputs or rounding.
Results are educational estimates, not tax, legal, investment, or medical advice, and not a loan offer. Verify filings and payments with the official authority or a qualified professional.