％ Percentage Calculator
Four calculators in one: find a percentage of a number, work out what percent one number is of another, and measure change or difference.
What is X% of Y?
X is what % of Y?
Percentage change from X to Y
Percentage difference between X and Y
How to use the Percentage Calculator
- Pick the calculator that matches your question.
- Enter the two numbers.
- Read the result, which updates instantly.
Examples
- 20% of 150 = 30.
- 45 is 75% of 60.
- From 80 to 100 is a 25% increase.
- Between 50 and 70 the percentage difference is about 33.33%.
Formula and method
X% of Y = X ÷ 100 × Y. X is what % of Y = X ÷ Y × 100. Change = (new − old) ÷ |old| × 100. Difference = |a − b| ÷ |(a + b) ÷ 2| × 100.
Frequently asked questions
Why does a 20% rise followed by a 20% fall not return to the start?
Each percentage uses a different base, so the second change is applied to a larger number.
What happens if I divide by zero?
The calculator shows a message instead of a result because the percentage is undefined.
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Helpful guides
How to Calculate Percentages: A Simple Guide · Browse all guides