Percentage Calculator
Quickly calculate what X% of an amount is. Useful for discounts, tips, commissions, or any everyday percentage calculation.
How is it calculated?
Result = (value × percentage) ÷ 100. For example, 20% of 250 is (250 × 20) ÷ 100 = 50.
Examples
20% of 250
20% of 250 is 50.
15% of 80
15% of 80 is 12.
How to calculate the percentage of an amount
To find X% of an amount, multiply the amount by X and divide by 100. 20% of 250 is 250 × 20 ÷ 100 = 50.
Another quick way: convert the percentage to a decimal (20% = 0.20) and multiply. Percentages with decimals, like 12.5%, work the same way.
The other percentage questions and how to solve them
This calculator solves the first row. For "what percentage is A of B", you can use the rule of three (B is 100%); to increase by a percentage, the percentage increase calculator; and for markdowns, the discount calculator.
| What you want to know | How to calculate it | Example |
|---|---|---|
| How much is X% of Y | Y × X ÷ 100 | 15% of 80 = 12 |
| What percentage is A of B | A ÷ B × 100 | 18 of 60 = 30% |
| Increase an amount by X% | Amount × (1 + X ÷ 100) | 200 + 10% = 220 |
| Decrease an amount by X% | Amount × (1 − X ÷ 100) | 200 − 10% = 180 |
| Percentage change between two values | (New − Original) ÷ Original × 100 | 50 to 60 = +20% |
Common mistakes with percentages
- Adding percentages from different bases: increasing by 10% and then decreasing by 10% doesn't return the original value (100 → 110 → 99).
- Calculating the percentage on the wrong amount: a "10% discount" applies to the original price, not the final one.
- Confusing percentage points with percentage: going from 20% to 25% is +5 points, but a +25% relative change.