Doubling Time Calculator
Exact years for an investment to double.
Your numbers
Years to double
10.24
Rule of 72 estimate
10.3
The link and the printed sheet both save your numbers, so anyone who opens them sees the same estimate.
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Save your current numbers, change them, save again, and see each estimate side by side. Saved in this browser only.
How it works
Years = ln 2 ÷ ln(1 + rate).
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Results are estimates for education only and are not investment advice.