Percentage Calculator
Choose the question you want answered and fill in the two known numbers. The calculator shows the answer and the working.
Result
- Working
- 20 ÷ 100 × 150 = 30
Formula
- X% of Y = X ÷ 100 × Y
- X as a percent of Y = X ÷ Y × 100
- Whole = part ÷ (percent ÷ 100)
How the Percentage Calculator works
Percent means per hundred. Twenty percent is 20 out of every 100, or the fraction 0.20. Every percentage problem relates three numbers: the part, the whole and the percentage. Knowing any two gives the third.
The third form is sometimes called a reverse percentage. If 30 is 20 percent of a number, divide 30 by 0.20 to recover the whole, 150.
Worked example
20% of 150 is 20 ÷ 100 × 150 = 30. Going the other way, 30 is 30 ÷ 150 × 100 = 20% of 150.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. 15 percent of 80 is 0.15 × 80 = 12.
How do I find what percent one number is of another?
Divide the first by the second and multiply by 100. 45 out of 60 is 45 ÷ 60 × 100 = 75 percent.
How do I find the original number from a percentage?
Divide the part by the percentage written as a decimal. If 36 is 12 percent of a number, the number is 36 ÷ 0.12 = 300.
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