Calculate simple interest on loans and investments instantly. Free interest calculator with principal, rate, and time inputs.
Simple Interest = Principal × Rate × Time. This formula ignores compounding. Good for short-term loans or basic calculations.
The tool runs in your browser using JavaScript. No server, no waiting. Enter your numbers, get instant results.
We use the standard simple interest formula. Results are accurate to multiple decimal places.
No. All calculations happen locally in your browser. Nothing leaves your device.
Yes. After loading the page, calculations work without internet connection.
For loans under one year, time can be entered as months (0.5, 0.25).
Compare simple vs compound interest for longer investments.
Double-check input values before calculating. A decimal error costs money.