What is simple interest?

Simple interest is calculated only on the original principal using I = PRT/100 (Principal x Rate x Time). Unlike compound interest, earned interest does not itself earn interest.

Where is simple interest used?

Short-term personal loans, some auto loans, bonds with fixed coupons, and many classroom finance problems use simple interest because it is straightforward to compute.

Simple vs compound interest - which grows faster?

Compound interest always grows faster over multiple periods because interest is added to the balance and earns its own interest. Over one single period they are identical.

Simple Interest Calculator

Calculate simple interest instantly using principal, rate, and time. See interest earned, total amount, and yearly interest.

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About Simple Interest Calculator

The simple interest calculator computes interest on the original principal only, for a fixed rate and period — the formula behind most short-term lending and deposits.

Simple interest applies to short-term loans, savings products, and notes where interest doesn't compound. This tool returns the interest earned or owed and the final amount with a single calculation.

When to Use Simple Interest Calculator

Use it for short-term deposit yields, small-business borrowings, or any loan where the interest is computed on the principal only.

Pro Tip

Simple interest and compound interest diverge the longer the term — for multi-year horizons, always check which applies.

Key Features

Processes Principal Amount, Interest Rate (% per year), Time Period (Years) directly in your browser
Produces interest earned, total amount instantly
Completely free with no usage limits
No registration or account required

How to Use

Provide the required inputs (Principal Amount, Interest Rate (% per year), Time Period (Years)).
The tool processes everything locally in your browser and instantly produces the following results: Interest Earned, Total Amount.
Review the result, then copy it to your clipboard or download the output file directly from this page.

Privacy note: Simple Interest Calculator runs 100% in your browser. Your data is never uploaded to any server, so nothing is stored or shared.

Benefits

Your data never leaves your device when using Simple Interest Calculator - everything runs locally
Get accurate results in seconds
Works on desktop, tablet, and mobile
No software download or installation needed