Estimate the years required to double your investment at a given annual rate of return.
Result
Rule of 72 is a quick approximation; exact time uses natural logarithms.
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Years to Double ≈ 72 / Interest Rate (%) | Exact = ln(2) / ln(1 + r)
12% return on ₹1,00,000.
Rule of 72: 6.00 Years | Exact Doubling: 6.12 Years to reach ₹2,00,000.
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Open calculatorThe Rule of 72 is a mental shortcut in finance: dividing 72 by the annual return rate gives a close approximation of the years required to double an investment.
The Rule of 72 accurately approximates compound growth for rates between 6% and 14%, providing quick comparisons between asset classes without complex financial modeling.