Simple Interest Calculator

Free simple interest calculator. Calculate interest using the formula I = P × R × T for loans, savings, and investments.

How the Simple Interest Calculator works

Simple interest accrues linearly based only on the original principal. The interest is calculated once using the principal, annual rate, and time period, then added to the principal for the total amount payable.

Formula

I = P × R × T / 100

How to use the Simple Interest Calculator

  1. 1The simple interest calculator is designed to be simple and fast.
  2. 2Enter the principal amount.
  3. 3Enter the annual interest rate.
  4. 4Enter the time period in years.
  5. 5Your result is shown immediately.

Examples

  • $10,000 at 5% for 3 years = $1,500 interest
  • $5,000 at 4% for 5 years = $1,000 interest

Benefits

  • Completely free with no signup required.
  • Runs entirely in your browser for instant results and privacy.
  • Works on mobile, tablet and desktop.
  • Results can be copied with one click.

Frequently Asked Questions

Is the simple interest calculator free to use?

Yes. The simple interest calculator is 100% free, with no signup, no watermark and no hidden limits.

Does the simple interest calculator store my data?

No. All calculations and processing happen locally in your browser. Nothing is uploaded to a server.

Does the simple interest calculator work on mobile?

Yes. The simple interest calculator is fully responsive and works on phones, tablets and desktop computers.

What is the simple interest formula?

Simple Interest = (Principal × Rate × Time) / 100. For example, $10,000 at 5% for 3 years = $1,500 interest.

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