Simple Interest Calculator: SI = P × R × T ÷ 100

Simple interest is charged only on the original amount. Enter the principal, yearly rate and number of years to see the interest and the total.

How to use the simple interest calculator

1. Type your numbers in the boxes (pick your currency or units if asked).
2. The answer updates as you type: no button to press.
3. Copy the result, or share it on WhatsApp with one tap.

Questions

What is the simple interest formula?

SI = P × R × T ÷ 100, where P is the principal, R the yearly rate in percent and T the time in years.

Is my data private?

Yes. Everything happens inside your own browser: nothing you type or choose is uploaded to us or anyone else.

Is it free?

Completely free, with no sign-up, no watermark and no limit on how many times you use it. Light ads keep the site running.