Financial Calculator
Rule of 72 Calculator
Estimate how long it takes money to double at a given annual return.
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Frequently asked questions
What is the Rule of 72?
The Rule of 72 is a shortcut for estimating how many years an investment may take to double by dividing 72 by its annual return percentage.
Does the Rule of 72 assume compound growth?
Yes. It approximates compound growth and is generally more useful for rates in a typical investing range than for extremely high or low rates.
Can I use the Rule of 72 for investment returns?
Yes, but the result assumes a steady annual return. Real investments fluctuate and may take more or less time to double.
Can the Rule of 72 estimate inflation effects?
Yes. Dividing 72 by an inflation rate estimates how long it could take prices to double if that inflation rate remains constant.
What are the limitations of the Rule of 72?
It is an approximation that ignores taxes, fees, changing rates, contributions, withdrawals, and uneven investment returns.