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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.
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.