Percentage Calculator

Calculate what is X% of Y, what percent X is of Y, and the percentage increase or decrease between two numbers.

Anyone working out discounts, tips, tax, grades, or statistics quickly.

How to use it

  1. Pick the calculation

    Choose the box that matches your question: percent of a number, one number as a percent of another, or a percentage change.

  2. Enter your numbers

    Type the values into the fields. Results update instantly as you type.

  3. Read the result

    The answer appears in bold. Percentage decreases show in red, increases in green.

Why use this tool?

Percentage questions come in a few standard forms, and mixing them up is a common source of mistakes. This tool separates the three most common ones — X% of Y, X as a percent of Y, and the percentage change between two numbers — so you always apply the right formula.

Common use cases

Shopping & discounts

Work out how much a percentage off saves you, or the percentage discount from two prices.

Grades & scores

Convert marks into percentages, e.g. 47 out of 60 as a percentage.

Finance & stats

Calculate percentage growth or decline between two figures like revenue or followers.

Frequently asked questions

How do I calculate percentage change?

Percentage change = (new − old) ÷ |old| × 100. The tool does this for you in the third box.

Does it handle decreases?

Yes. A drop from 100 to 80 shows as −20%, and an increase from 80 to 100 shows as +25%.

Is anything sent to a server?

No. All maths runs in your browser.

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