Rule of 72 Calculator — free online
Ever wondered how long it would take for your savings to double? There's an old shortcut for that called the Rule of 72, and it's surprisingly handy. We added a free tool that does the math for you — Rule of 72 Calculator — right in your browser.
What it does
You give it an interest or growth rate, and it tells you roughly how many years it takes to double your money. You can also flip it around: enter the number of years you have in mind, and it tells you the rate you'd need. No formulas to remember, just type a number.
Nothing leaves your device
The whole thing runs in your browser. Nothing is uploaded, nothing is saved on a server, and no one sees the numbers you type. When you close the tab, it's gone.
How to use it
- Open the Rule of 72 Calculator.
- Type a rate to see the years, or type the years to see the rate.
- Read the result right away — no button to wait on.
It's free with no limit. There are more small tools on the Apps page.