Percentage Calculator
Calculate a percentage of a number, find what percent one number is of another, or work out the percentage increase or decrease. Instant, free and private.
Runs in your browser. Nothing is uploaded.
What is X% of Y?
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X is what percent of Y?
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Percentage change from X to Y
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About this tool
Percentages come up everywhere: discounts, taxes, tips, grades, interest and statistics. This percentage calculator solves the three questions people ask most often, all on one screen: what is X% of Y, X is what percent of Y, and what is the percentage change from one value to another.
Every calculator updates as you type and explains the answer in a plain sentence, so you can check that you asked the right question. Percent change tells you whether a value went up or down and by how much, using the absolute starting value so it also works with negative numbers. Division by zero and invalid input are reported clearly instead of showing a wrong result.
How to use it
- Find the calculator that matches your question: “percent of a number”, “what percent” or “percentage change”.
- Enter the two numbers in the fields. The default values show an example you can overwrite.
- Read the highlighted result. The sentence below it restates the calculation in words.
- Change any number to recalculate instantly. You can use decimals and negative numbers.
Frequently asked questions
How do I calculate a discount?
Use the first calculator to find the discount amount. For a 25% discount on 80, enter 25 and 80 to get 20, then subtract it from the price: 80 − 20 = 60.
How is percentage change calculated?
It is the difference between the new and the old value, divided by the old value, multiplied by 100. Going from 80 to 100 is a 25% increase because 20 ÷ 80 = 0.25.
Why can’t I calculate a change from zero?
A percentage change is relative to the starting value, and nothing can be divided by zero. If the starting value is zero, the percentage change is undefined.
Can a percentage be greater than 100?
Yes. 150% of a number is one and a half times that number. A value that triples has increased by 200%.
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