📈 Compound Interest Calculator
Instantly calculate compound interest and project your investment's future value — including monthly contributions — free and entirely in your browser with no login or file upload required.
Inputs
Future Value
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Total Contributions
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Total Interest Earned
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About
This tool computes compound interest using daily, monthly, quarterly, or annual compounding, and generates a full year-by-year breakdown of your balance, contributions, and interest earned — all exportable as CSV. Because every calculation runs locally in your browser, your financial figures never leave your device and no account is needed.
How to use
- Enter your starting principal (e.g. $10,000).
- Set the annual interest rate and investment period in years.
- Choose a compounding frequency: daily, monthly, quarterly, or annually.
- Optionally add a monthly contribution to model regular savings.
- View the future value, total interest earned, and year-by-year table — then copy or download the results as CSV.
FAQ
- Is this compound interest calculator free?
- Yes, completely free with no account, subscription, or hidden fee required.
- Does it upload my financial data to a server?
- No. All calculations run 100% in your browser — your numbers never leave your device.
- Does it work offline or without an internet connection?
- Yes. Once the page is loaded, no network connection is needed. It works fully offline.
- Which compounding frequencies are supported?
- Daily (365×/year), monthly (12×), quarterly (4×), and annually (1×) compounding are all supported.
- Can I include regular monthly savings contributions?
- Yes. Enter any monthly contribution amount and the calculator factors it into each period's balance and the year-by-year breakdown.