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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Increase/decrease X by Y%
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What This Tool Does
Four percentage calculators in one page, each updating live as you type. Covers the most common percentage problems: finding a percentage of a value, expressing one number as a percentage of another, calculating percentage change between two values, and adjusting a value up or down by a percentage.
Frequently Asked Questions
What types of percentage calculations does this tool cover?
Four common types: (1) X% of Y — e.g. what is 15% of 80? (2) X is what % of Y — e.g. 12 is what percent of 80? (3) Percentage change — what is the % increase or decrease from X to Y? (4) Increase/decrease a value by a percentage — e.g. 80 increased by 15%.
How is percentage change calculated?
Percentage change = ((New Value − Old Value) / Old Value) × 100. A positive result is an increase; negative is a decrease.
Is my data sent to a server?
No. All calculations run in your browser. Nothing is transmitted anywhere.