Percentage Calculator
Find a percentage of a number, what percent one number is of another, or the percent change between two numbers.
- Answer
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How it is calculated
- A% of B = A ÷ 100 × B
- A as a % of B = A ÷ B × 100
- % change from A to B = (B − A) ÷ |A| × 100
Worked example
15% of 200.
| You enter | |
|---|---|
| What do you want to find? | A% of B |
| A | 15 |
| B | 200 |
| You get | |
| Answer | 30 |
Questions
Why does the percent change use |A|?
So a rise from a negative starting value still shows as a positive change, which is the usual convention.
Is a 50% rise then a 50% fall back to the start?
No. 100 rises 50% to 150, then falls 50% to 75. Each percentage applies to a different base.
Sources and checks
Last checked: 12 October 2026. This calculator passes 9 automatic tests before every release.
Results are estimates for information only and are not financial, tax or legal advice. Check important figures with a qualified professional before you act on them.