Free Percentage Calculator

Three calculators in one: percentage of a number, percentage of a total, and percentage change.

What is X% of Y?

of

10

X is what % of Y?

of

12.5%

Percentage change from X to Y

→

+25%

Percentages show up everywhere — discounts, tips, exam scores, price changes — and the three common questions all need a slightly different formula. This page covers all three, so you don’t have to remember which one to use.

Everything updates instantly as you type, entirely in your browser.

How to use it

  1. Pick the calculator that matches your question (percentage of a number, what percent, or percentage change).
  2. Type your two numbers.
  3. Read the result — it updates as you type.

Frequently asked questions

How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number. For example, 20% of 50 is (20 ÷ 100) × 50 = 10. That’s the first calculator on this page.

How do I find out what percentage one number is of another?

Divide the first number by the second, then multiply by 100. For example, 25 out of 200 is (25 ÷ 200) × 100 = 12.5%. That’s the second calculator.

How is percentage increase or decrease calculated?

Subtract the old value from the new value, divide by the old value, then multiply by 100. A negative result means a decrease. That’s the third calculator: enter the “from” and “to” numbers.

Why does the third calculator show a negative number sometimes?

A negative percentage means the value went down. For example, going from 100 to 80 is a −20% change.

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