Simple Interest Calculator
Calculate simple interest on principal, rate and time. Free, fast and private.
Your result will appear here.
Formula: Simple Interest I = P × R × T ÷ 100, and total amount A = P + I. Results are indicative estimates, not financial advice.
How to use Simple Interest Calculator
- Enter the principal amount.
- Enter the annual interest rate and the time in years.
- Click Calculate to see the simple interest and the total amount.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
What is simple interest?
Simple interest is calculated only on the original principal, never on interest already earned — unlike compound interest.
How is simple interest calculated?
I = P × R × T ÷ 100, where P is the principal, R is the annual rate in percent and T is the time in years.
When is simple interest used?
For short-term loans, some savings accounts and basic interest problems. Long-term investments usually use compound interest.
Is this simple interest calculator free?
Yes, it is 100% free with no sign-up. Your data stays in your browser.