About the Compound Interest Calculator
See how your savings grow when interest is added to interest, with optional monthly deposits. This tool is free, works in your browser and needs no sign-up.
How to use the Compound Interest Calculator
Enter your starting amount, yearly rate, number of years and how often interest compounds. Add a monthly deposit if you plan to save regularly.
Formula used
Balance = P × (1 + r ÷ n)^(n × t). Monthly deposits are added every month and earn the same effective rate.
Example
10,000 at 8% compounded yearly for 10 years grows to about 21,589.
Frequently asked questions
Is the Compound Interest Calculator free to use?
Yes. It is completely free and you can use it as many times as you like.
How accurate is the Compound Interest Calculator?
The calculator uses standard formulas, so the maths is exact. Real life results can differ because of fees, taxes, rounding or personal factors, so treat the answer as an estimate.
Do you store the numbers I enter?
No. All calculations run in your browser. The values you type are not sent to our server.
Disclaimer: results are estimates for information only. They are not financial, medical or professional advice.