How to calculate a percentage
A percentage represents a number as a part of 100. The word "percent" means "per hundred."
Finding a percentage of a number
To find X% of Y, multiply Y by X and divide the result by 100.
X% of Y = (X ÷ 100) × Y
For example, 20% of 150 is 30.
Finding what percentage one number is of another
Divide the first number by the total number and multiply by 100.
Percentage = (Part ÷ Total) × 100
For example, 30 is 20% of 150.
Calculating percentage change
Percentage change compares an original value with a new value.
Percentage Change = ((New − Original) ÷ Original) × 100
A positive result represents an increase, while a negative result represents a decrease.
Percentage examples
What is 15% of 200?
15 ÷ 100 × 200 = 30
50 is what percentage of 200?
50 ÷ 200 × 100 = 25%
A price increases from 100 to 120. What is the percentage increase?
(120 − 100) ÷ 100 × 100 = 20%
Frequently asked questions
A percentage is a way of expressing a number as a fraction of 100.
For example, 25% means 25 out of 100.
Divide the percentage by 100 and multiply it by the number.
For example, 10% of 500 is 50.
Subtract the original value from the new value, divide by the original
value, and multiply by 100.
Yes. A negative percentage change means the new value is lower than
the original value.