Percentage Calculator
Percentage calculator for seven questions: X% of Y, X is what % of Y, percent change, percent difference, X is Y% of what, and a percent increase or decrease. How it works
Use the Percentage Calculator
About the Percentage Calculator
15% of 200 is 30: divide the percent by 100 and multiply, 0.15 × 200. This percentage calculator also tells you what percent one number is of another (50 is 25% of 200), the percent change between two numbers (50 to 75 is +50%), their percent difference (50 and 75 differ by 40%), the whole behind a part (12 is 15% of 80), and a number raised or cut by a percent (80 plus 25% is 100).
X percent of Y: common values
| Percent | of 50 | of 80 | of 100 | of 150 | of 200 | of 500 |
|---|---|---|---|---|---|---|
| 5% | 2.5 | 4 | 5 | 7.5 | 10 | 25 |
| 10% | 5 | 8 | 10 | 15 | 20 | 50 |
| 15% | 7.5 | 12 | 15 | 22.5 | 30 | 75 |
| 20% | 10 | 16 | 20 | 30 | 40 | 100 |
| 25% | 12.5 | 20 | 25 | 37.5 | 50 | 125 |
| 30% | 15 | 24 | 30 | 45 | 60 | 150 |
| 50% | 25 | 40 | 50 | 75 | 100 | 250 |
| 75% | 37.5 | 60 | 75 | 112.5 | 150 | 375 |
Read across: 15% of 80 is 12, and 20% of 150 is 30.
X is what percent of Y
| Part of whole | Percent |
|---|---|
| 1 of 12 | 8.3333% |
| 1 of 8 | 12.5% |
| 1 of 6 | 16.6667% |
| 1 of 5 | 20% |
| 1 of 4 | 25% |
| 1 of 3 | 33.3333% |
| 3 of 8 | 37.5% |
| 1 of 2 | 50% |
| 5 of 8 | 62.5% |
| 2 of 3 | 66.6667% |
| 3 of 4 | 75% |
| 7 of 8 | 87.5% |
Rounded to 4 decimal places, as the calculator shows them. 1 of 3 is 33.3333…% with the 3 repeating.
Percent change between two numbers
| Old to new | Percent change |
|---|---|
| 50 to 75 | +50% |
| 80 to 60 | -25% |
| 200 to 250 | +25% |
| 40 to 50 | +25% |
| 50 to 40 | -20% |
| 100 to 150 | +50% |
| 150 to 100 | -33.3333% |
| 100 to 200 | +100% |
| 200 to 100 | -50% |
| 20 to 60 | +200% |
A rise and the fall that undoes it are different percents, because each is measured against its own starting number: 40 to 50 is +25%, and 50 back to 40 is -20%.
How to use this tool
- Pick the tab that matches your question: X% of Y, X is what % of Y, % change, X is Y% of what, Increase by %, Decrease by % or % difference.
- Type the two numbers. The result appears as you type, rounded to 4 decimal places.
- Copy or share the result with the buttons under it. Earlier calculations are kept in a history list in this browser, and you can reopen or clear them.
Frequently asked questions
- What is 20 percent of 150?
- 30. Divide 20 by 100 to get 0.2, then multiply: 0.2 × 150 = 30. The same two steps give 15% of 80 = 12 and 25% of 200 = 50.
- How do I calculate what percent one number is of another?
- Divide the part by the whole and multiply by 100. 30 out of 40 is 30 ÷ 40 × 100 = 75%. 1 out of 3 is 33.3333%, rounded to 4 decimal places.
- How do I calculate percent change?
- Subtract the old number from the new one, divide by the old number and multiply by 100. From 80 to 100 is (100 − 80) ÷ 80 × 100 = +25%. From 100 to 80 is -20%, because the same 20 is now measured against 100. When neither number is the starting point, use % difference: it divides by the mean of the two sizes, |a − b| ÷ ((|a| + |b|) ÷ 2) × 100, so 80 and 100 differ by 22.2222% in either order.
- How do I find the original number when I know a percent of it?
- Use the X is Y% of what tab: divide the amount by the percent and multiply by 100. If 12 is 15% of a number, the number is 12 ÷ 15 × 100 = 80. To undo a discount, ask what the sale price is a percent of: 60 after 25% off is 75% of the original, and 60 is 75% of 80.
- Why does a 50% increase followed by a 50% decrease not bring me back to where I started?
- The second percent is taken from a bigger number. 100 increased by 50% is 150, and 150 decreased by 50% is 75. Getting from 150 back to 100 takes a 33.3333% decrease.
- Can I calculate a percent change from zero or between negative numbers?
- Not from zero: the change would have to be divided by 0, so the calculator shows a message and no number. Negative starting values work. The change is divided by the absolute value of the start, so going from -50 to -25 is +50%.
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