Compound Interest Calculator
See how savings or investments grow over time with compound interest.
Final balance
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Usage examples
Previewing how long-term savings grow
Enter the principal, rate, and number of years to instantly see how much compound interest grows your money.
Calculating a recurring contribution plan
Enter a regular contribution amount to see the final balance if you keep adding to the account like a recurring savings plan.
Comparing different compounding frequencies
See how the final balance changes depending on whether interest compounds annually, monthly, or daily, even at the same rate.
Frequently asked questions
Is the amount I enter sent to a server?
No. All calculation happens entirely in your browser, and the amount you enter is never sent to a server.
Does this exactly match a real savings account's interest?
This calculator is an estimate using the standard compound interest formula. Real financial products may differ due to taxes, fees, and promotional rate conditions.
When is the contribution assumed to be made?
Contributions are assumed to be made at the end of each compounding period.
Which compounding frequency should I choose?
For the most accurate estimate, match the frequency to how the account you're considering actually compounds interest. If you're not sure, monthly is the most common for typical savings accounts.