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Doubling Time Calculator
Use this page to estimate how long it takes money to double at a given annual rate, or what annual rate you need to double money within a chosen number of years.
Rule of 72 estimate in years to double
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Exact compound estimate
—The exact result uses compound math. The Rule of 72 is a shortcut that is close in many normal ranges but not perfect.
How to use this page
- Use rate to years when you know the expected annual return and want a quick doubling estimate.
- Use years to rate when you know the doubling deadline and want to see the annual return that would imply.
- Use exact math for planning and the Rule of 72 for a quick sanity check.