Simple Interest Calculator
Basic interest calculation
Use this when you need a fast, accurate result — no sign-up, works entirely in your browser.
Interest—
Total amount—
How to Use
- Enter your details into the fields above.
- Click the calculate button to get your result instantly.
- Use the clear button to start a new calculation.
Example
- $5,000 at 4% for 3 years → $600 interest; $5,600 total
- $8,000, 3.5%, 4 years (simple) → Interest $1,120; total $9,120
Formula
Interest = P × r × t, and total = P + interest. Interest is never added to the principal here, so it never earns interest of its own — over long periods this gives much less than compounding.
About Simple Interest Calculator
Basic interest calculation. This free online tool gives you fast, accurate results without registration or downloads.
Everything runs locally in your browser, so your data is never uploaded or stored — privacy first.
Frequently Asked Questions
Is the Simple Interest Calculator free to use? +
Yes, the Simple Interest Calculator is completely free with no registration, login, or download required.
Is my financial data private? +
Yes. All calculations happen locally in your browser. Your numbers are never uploaded or stored on our servers.
Can I use the Simple Interest Calculator on mobile? +
Yes, it works on any device — phone, tablet, or desktop — with instant results.