Simple Interest Calculator
Interest = principal × rate × time, computed instantly.
How to use the Simple Interest tool
- Enter your simple interest in the fields above.
- Adjust any slider or type an exact number — the answer updates as you go.
- Copy the result and close the tab. Nothing you entered was sent anywhere.
About the Simple Interest tool
Enter a principal, an annual interest rate and a time period to get the interest earned or owed and the final balance. Supports years, months or days.
Simple interest pays only on the original principal. If interest should also earn interest, use the compound interest calculator instead.
Everything runs locally in your browser: no data is uploaded, no account is needed, and it works offline once the page has loaded.
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