Percentage Calculator
Three percentage calculations in one tool: what is X% of Y, X is what percent of Y, and percent change from X to Y.
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Result
Enter your details on the left, then press Calculate.
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Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100, then multiply by the number. Example: 20% of 150 = (20/100) × 150 = 30.
What does percent change mean?
Percent change measures how much a value has grown or shrunk relative to its starting value. The formula is (new − old) ÷ old × 100. A positive result is an increase, negative is a decrease.
Why does the calculator say 'Y cannot be 0'?
Division by zero is undefined in mathematics. When calculating 'X is what % of Y', Y is the denominator — it must be non-zero for the answer to exist.