Free tool · runs in your browser

Percentage calculator

Work out a percentage of a number, what percent one number is of another, or the percentage change from one number to another.

What is% of= 12

is what % of= 25%

Fromtois a change of= +30%

Type any numbers; decimals and negative values work. Results update as you type.

Quick answer

Three calculators in one: X% of Y is X ÷ 100 × Y (15% of 80 = 12); X is what % of Y is X ÷ Y × 100 (30 of 120 = 25%); and percentage change from A to B is (B − A) ÷ A × 100 (50 to 65 = +30%). Results update as you type, and decimals and negative numbers work.

How to use it

Pick the question. X% of a number, what percent one number is of another, or the change between two numbers.
Type the two numbers. Decimals with a dot or comma both work.
Read the answer. The result appears at once next to the question.

Example

The three calculators with sample numbers:

Input

What is 15% of 80?
30 is what % of 120?
From 50 to 65?

Output

= 12
= 25%
= +30%

Common errors and how to fix them

Two discounts were added together: 20% and then 10% off is 28% off, not 30%, because the second applies to the reduced price.
Percent and percentage points were mixed up: Going from 5% to 7% is 2 percentage points, or a 40% increase. Say which one you mean.
A 50% fall and 50% rise did not cancel out: The rise is on the smaller number: 100 → 50 → 75. To get back to 100, you need a 100% rise.
The change from 0 shows a dash: Percentage change from zero is undefined. Report the absolute change instead.

Frequently asked questions

How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number: 15% of 80 is 0.15 × 80 = 12.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100: 30 out of 120 is 30 ÷ 120 × 100 = 25%.

How do I calculate percentage increase?

Subtract the old value from the new one, divide by the old value and multiply by 100: from 50 to 65 is 15 ÷ 50 × 100 = +30%.

How do I calculate a discount?

Multiply the price by the discount and subtract it: 20% off 250 is 250 − 50 = 200. Or multiply by 0.8 directly.

Are two discounts of 20% and 10% the same as 30%?

No. They apply one after another: 100 × 0.8 × 0.9 = 72, which is 28% off.

What is the difference between percent and percentage points?

A rate rising from 5% to 7% rises by 2 percentage points but by 40 percent.

Why does a 50% drop and a 50% rise not cancel out?

The rise is calculated on the smaller number: 100 drops to 50, and 50% of 50 brings it only to 75.

How do I add VAT or tax?

Multiply by 1 plus the rate: 100 plus 17% VAT is 100 × 1.17 = 117.

How do I reverse a percentage?

Divide by 1 plus the rate: a price of 117 including 17% tax was 117 ÷ 1.17 = 100 before tax.

Why is percentage change from zero not shown?

Any change from zero is an infinite percentage, so it cannot be calculated. Report the absolute change instead.