Investment Calculators

Rule of 72 Calculator

Quick estimate of how long an investment will take to double at a given annual return.

About the calculator

What is the Rule of 72 Calculator?

The Rule of 72 Calculator is a free online tool that helps you make informed decisions about your money. Enter your numbers and the calculator gives you instant, accurate results.

Use it to compare scenarios, plan goals and validate assumptions — all without signing up.

Formula used
  • Rule of 72
    Years to double ≈ 72 / Rate (%)

Why use the Rule of 72 Calculator?

Financial planning works only when it's specific. The Rule of 72 Calculator converts assumptions into concrete numbers — so you can choose between scenarios with confidence rather than guesswork.

How it helps

By tweaking inputs and instantly seeing the impact, you build intuition for how the underlying variables interact. This is far more useful than abstract formulas alone.

What to remember

Calculators show possible outcomes based on the assumptions you provide. Real-world results may vary; review your plan periodically and adjust as your income, goals and circumstances evolve.

Frequently Asked Questions

A quick mental approximation: divide 72 by the annual return to estimate doubling time.
It's a close estimate for rates between 6% and 12%; less so at extreme rates.
Best for compounded growth — FDs, equity index returns, savings instruments.
For tripling (114) and quadrupling (144) — same idea, different numerators.
Yes — at 6% inflation, money halves in purchasing power in ~12 years.
It's a great heuristic; for precise planning use the compound interest calculator.

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