Rule of 72 Calculator to estimate how long it may take for your investment to double based on a fixed annual interest rate.
Rule of 72 Calculator
0500k1M
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Rule of 72 assumes annual compounding. Changing this affects the "Exact" calculation only.
Uses Rule of 72. For 3x/4x, it uses Rule of 115 / Rule of 144.
Results
Rule of 72: Time to Double
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Exact Time to Double
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Difference (Error)
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Value at Rule of 72 Time
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Value at Exact Time
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Total Interest Earned
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Effective Annual Rate
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Composition at Exact Target
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Composition at Exact Target
Initial Principal
Interest Earned
Growth Timeline to Target
Balance
Rule of 72 Target Time
Exact Target Time
Sensitivity: Time to Target at Various Rates
How long it takes to reach your target at different interest rates
Year-by-Year Growth
| Year | Balance | Interest Earned | Growth % | Progress to Target |
|---|