Compound Interest Calculator
Project how your savings grow with compound interest and regular contributions. Runs entirely in your browser. Nothing you type is ever uploaded.
What can you calculate?
GrowGoal projects a savings or investment balance forward from a starting amount, a regular monthly contribution, an annual interest rate, and a time horizon, using your choice of compounding frequency, and breaks the result down into total contributed versus total interest earned.
Want the mental-math shortcut for how long money takes to double? Read The Rule of 72, and Why Compound Interest Feels Slow, Then Fast.
How it works
Every calculation runs directly in your browser using the standard compound interest formula. Nothing is sent to a server, so it works even offline once the page has loaded.
Frequently asked questions
Is this free to use?
Yes. There's no sign-up and no limit on how many calculations you run.
Do you store what I type?
No. Every calculation happens entirely client-side in your browser. See the privacy policy for details.
How is the future value calculated?
It compounds your starting balance at the given annual rate over the chosen compounding frequency, and adds each regular contribution at the same frequency, letting each one compound for the remaining time. The result is your projected balance, total contributed, and total interest earned.
Does this account for taxes or inflation?
No. It projects nominal growth at the interest rate you enter, before taxes and before adjusting for inflation. For a real (inflation-adjusted) projection, you can enter your expected real rate of return instead of the nominal rate.