Percentage Calculator

Use this free percentage calculator to find a percentage of a number, work out what percent one number is of another, or measure the percentage change between two values. Results are rounded to 2 decimal places.

What is X% of Y?

X is what percent of Y?

Percentage change from X to Y

Commas and spaces in numbers are ignored. Negative numbers are allowed.

How it works

A percentage is a number out of 100. The calculator turns your inputs into one of three standard formulas and rounds the answer to 2 decimal places (halves round away from zero).

Formulas

  • X% of Y = X × Y ÷ 100
  • X is what percent of Y = X ÷ Y × 100 (Y cannot be 0)
  • Percentage change = (Y − X) ÷ |X| × 100 (X cannot be 0)

Steps

  1. Pick the calculator that matches your question.
  2. Type your two numbers into the boxes.
  3. Press Calculate and read the result and the worked line under it.

Examples

  • 15% of 240 = 15 × 240 ÷ 100 = 36
  • 45 is what percent of 60? 45 ÷ 60 × 100 = 75%
  • Price rises from 800 to 1,000: (1,000 − 800) ÷ 800 × 100 = 25% increase

Common uses

Working out discounts and sales tax, checking exam scores, comparing salaries before and after a raise, and measuring growth in prices, sales or savings.

Frequently asked questions

How do I find a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 20% of 50 is 20 × 50 ÷ 100 = 10.

Why can’t I divide by 0?

A percentage of 0 has no meaning, so “X is what percent of 0” and “change from 0” have no answer. The calculator shows a message instead of a result.

What happens if the old value is negative?

Change is measured against the size of the old value, ignoring its sign. Going from −50 to −25 is shown as a 50% increase because the value moved up by half of 50.

Is percentage change the same as percentage points?

No. Going from 10% to 15% is a change of 5 percentage points, but a 50% increase in the rate itself.

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