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Rule of 72 calculator
A back-of-envelope classic: divide 72 by your annual return to estimate the doubling time.
Years to double
10.3 yrs
21 yrsYears to 4×
Educational estimate — not individualized financial advice. Assumes steady rates; excludes taxes and fees unless stated.
How it works
The rule of 72 is an approximation of the exact logarithmic doubling time — close for returns in the 4–12% range.