Percentage Calculator
Answer everyday percentage questions: what is X% of Y, what percentage is X of Y, and the percentage change between two numbers — with the formula shown for each.
Examples
15% of 200
30
How it works
The calculator answers three different questions, and each uses its own formula. Results are rounded to two decimal places and the working is shown under the answer.
| Question | Formula | Example |
|---|---|---|
| What is X% of Y? | X ÷ 100 × Y | 15% of 200 = 30 |
| X is what % of Y? | X ÷ Y × 100 | 30 of 200 = 15% |
| % change from X to Y | (Y − X) ÷ X × 100 | 200 to 250 = +25% |
Percentage change is not symmetrical: going from 200 to 250 is a 25% rise, but going back from 250 to 200 is a 20% fall, because the starting number is different. A change that starts from zero has no percentage, since it would mean dividing by zero.
How to use Percentage Calculator
Why use this tool
Frequently asked questions
(new − old) ÷ |old| × 100. A positive result is an increase, a negative result is a decrease.
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