Rule of 72 & Doubling Time Calculator
Rule of 72 & Doubling Time Calculator
Instructions: Enter any 1 parameters and leave 1 parameter empty to calculate the missing value.
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Calculation Results
Doubling Time
How to Calculate Doubling Time?
Exact Formula: t = ln(2) / ln(1 + r)
Where:
- t = doubling time (in periods)
- r = interest rate per period (as decimal)
- ln = natural logarithm
Reverse Formula (Calculate Interest Rate): r = exp(ln(2) / t) - 1
Rule of 72 Approximation: t ≈ 72 / (interest rate as percentage)
How Long Does It Take to Double Your Money?
- 6% Annual Return: Money doubles in approximately 11.9 years
- 8% Annual Return: Money doubles in approximately 9.0 years
- 10% Annual Return: Money doubles in approximately 7.3 years
- 12% Annual Return: Money doubles in approximately 6.1 years
How Long Will It Take for $10,000 to Double at 7 Compound Interest?
It will take approximately 10.24 years for $10,000 to double at 7% compound interest annually. This matches closely with the Rule of 72 estimate of about 10.29 years.
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