Percentage of a Number
Find out what X% of Y is. Type either value and the result updates instantly.
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How to work out a percentage of a number
- Type the percentage, for example
15. - Type the number you want a percentage of, for example
200. - The answer appears straight away: 15% of 200 is 30.
The formula
result = (percentage ÷ 100) × number
For example, 15% of 200 is (15 ÷ 100) × 200 = 30. This is the calculation behind tips, discounts, taxes, commissions, and most everyday percentage questions.
Questions about percentages
How do I calculate a percentage of a number by hand?
Divide the percentage by 100 and multiply by the number. For 20% of 80: 20 ÷ 100 = 0.2, and 0.2 × 80 = 16.
What is a quick way to find 10% or 5% in my head?
To find 10%, move the decimal point one place left: 10% of 350 is 35. Halve that for 5% (17.5), and double it for 20% (70).
Is X% of Y the same as Y% of X?
Yes. 8% of 50 and 50% of 8 are both 4, so you can swap them if one way round is easier to work out.
How do I add a percentage to a number?
Multiply by 1 plus the percentage as a decimal: adding 20% to 50 is 50 × 1.2 = 60. The percentage increase calculator does this for you.