Simple Interest Calculator
Interest and total from principal, rate and time.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Founders, analysts and investors rely on the free Simple Interest Calculator to nail Simple Interest in seconds — no spreadsheets, no sign-up. Enter your numbers, get an accurate result instantly, and compare scenarios to make smarter pricing, budgeting and growth calls.
About Simple Interest Calculator
Simple interest is interest charged only on the original principal, not on accumulated interest. The formula is simple: Interest = Principal × Rate × Time. For example, $5,000 at 6% for 3 years earns $900 in interest. The free Simple Interest Calculator does the math for you — just enter the principal, annual interest rate and time in years and read the result instantly. It runs entirely in your browser with no sign-up, no limits and nothing to install.
How to use Simple Interest Calculator
- 1Enter the principal, annual interest rate and time in years into the calculator.
- 2The Simple Interest is computed automatically using the formula Interest = Principal × Rate × Time — there's no button to press.
- 3Change any input to model a different scenario, then note or copy the result.
Why use Simple Interest Calculator?
- ✓Calculates Simple Interest instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the numbers you enter stay private
- ✓Updates live as you type — perfect for comparing scenarios
Frequently asked questions
How do you calculate Simple Interest?+
Simple interest is interest charged only on the original principal, not on accumulated interest. The formula is: Interest = Principal × Rate × Time. For example, $5,000 at 6% for 3 years earns $900 in interest.
Simple vs compound interest?+
Simple interest is calculated only on the principal; compound interest also earns interest on previously accrued interest, so it grows faster.
Is the Simple Interest Calculator free to use?+
Yes — it's completely free, with no sign-up, no login and no usage limits. You can run it as many times as you like.
Is my data private?+
Yes. The Simple Interest Calculator runs entirely in your browser, so the figures you enter are never uploaded or stored on any server.
Embed Simple Interest Calculator on your website
Want Simple Interest Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
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