Percentage Calculator
Work out any percentage — X% of a number, one number as a percent of another, percentage change, or adding/subtracting a percent.
- Browser-based
- Free
- No signup
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Result
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- How it's calculated—
All calculations run entirely in your browser — nothing is uploaded.
Generated entirely in your browser.
Frequently asked questions
- How do I calculate what X% of Y is?
- Multiply the number by the percentage, then divide by 100. For example, 15% of 200 = 15 × 200 ÷ 100 = 30. The 'What is X% of Y?' mode does this for you instantly.
- How do I find what percentage one number is of another?
- Divide the part by the whole and multiply by 100. For example, 30 is what % of 200? → 30 ÷ 200 × 100 = 15%. Use the 'X is what % of Y?' mode.
- How do I calculate percentage increase or decrease?
- Subtract the old value from the new value, divide by the old value, then multiply by 100. A rise from 200 to 250 is (250 − 200) ÷ 200 × 100 = 25% increase. The '% change' mode shows increase or decrease automatically.
- Is my data uploaded anywhere?
- No. The percentage calculator runs entirely in your browser — no numbers are sent to a server, nothing is stored, and no signup is needed.