Rule of 72 Calculator
Quickly estimate how many years it takes for your money to double at a given return.
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The Rule of 72 (and its variants, 114 to triple and 144 to quadruple) is a quick mental-math approximation, not an exact calculation.
Estimates only. Figures are indicative and do not constitute financial advice.
About the Rule of 72 Calculator
"Rule of 72 calculator," "paisa double karne ka formula," or simply "money doubling calculator" — all searched by investors who want a fast mental-math shortcut for how long it takes an investment to double. No compound interest formula required: just divide 72 by your expected annual return rate to get an approximate number of years, a trick worth actually remembering since it comes up constantly when comparing investment options.
The Rule of 72 is a well-known approximation that lets you quickly compare how different return rates affect your investment timeline — at 12% returns, your money roughly doubles in 6 years; at 8%, it takes about 9 years; at a bank FD's typical 6-7%, closer to 10-12 years. This calculator also shows the lesser-known variants: the Rule of 114 for tripling your money, and Rule of 144 for quadrupling it, at the same rate — useful if you're mentally comparing a mutual fund SIP against a fixed deposit or PPF and want a quick sense of "how many years to double my paisa" at each option's expected return, without pulling out a full compound-interest calculator every time.
How to use this calculator
- Enter your expected annual return rate.
- See the approximate years to double, triple, and quadruple your investment.
Frequently asked questions
›How accurate is the Rule of 72?
It's a close approximation for typical return rates (roughly 6-12%), with slightly more error at very low or very high rates — for precise calculations, use a full compound interest formula instead.
›What is the Rule of 114 and Rule of 144?
Companion approximations to the Rule of 72 — dividing 114 by your return rate estimates years to triple your money, and 144 estimates years to quadruple it.
›Does the Rule of 72 work for any interest rate?
It works reasonably well for typical investment return rates; at very high rates (above roughly 20%) the approximation becomes noticeably less accurate compared to the exact compound interest calculation.
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Read the full guide
The Rule of 72: How Fast Your Money Actually Doubles