Simple Interest Calculator

Calculate simple interest and the final amount from principal, rate and time. Free to use online with no sign-up. Fast and mobile-friendly.

Simple interest is calculated only on the original principal, so it grows at a constant rate.

Formula

Interest = principal × annual rate × time.

Example

5,000 at 6% for 3 years earns 900 in simple interest.

Frequently asked questions

Is the simple interest calculator free to use?: Yes. The tool is free to use and does not require an account.
Is my input stored?: For browser-based tools, your input stays on your device. The URL shortener is the exception because short links must be stored to redirect later.