Monu Tools

Percentage Calculator

Work out percentages six ways: a percent of a value, what percent one number is of another, the base behind a percent, percentage change, increase or decrease, and percentage difference.

How to use the Percentage Calculator

  1. 01

    Pick the type of calculation you need from the dropdown.

  2. 02

    Enter the two values. The labels change to match the chosen calculation.

  3. 03

    Read the result and the plain-language explanation below it.

Frequently asked questions

How do I calculate X percent of a number?

Choose 'What is X % of Y?', enter the percentage and the base value. The tool multiplies the base by the percentage divided by 100. For example, 25 % of 200 is 50.

How do I work out a percentage change?

Choose 'Percentage change from X to Y' and enter the old and new values. The change is the difference divided by the old value, times 100. A drop gives a negative percentage.

What is the difference between percentage change and percentage difference?

Percentage change compares a new value against a starting value and has a direction (up or down). Percentage difference compares two values against their average and is always positive.

Does the calculator round?

Results are shown with up to two decimal places for readability, but the full value is used in the maths. Nothing is sent anywhere; everything runs in your browser.

About this tool

The percentage calculator covers the calculations people reach for most often: finding a percentage of a value, expressing one number as a percentage of another, finding the base value behind a percentage, percentage increase and decrease, and the percentage change or difference between two numbers.

Each mode shows a clear result plus a short sentence that spells out the calculation, so you can check the logic at a glance. It is handy for discounts, tips, taxes, grades, statistics and everyday maths.

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