How to calculate percentages
A percentage is just a fraction of 100. These three calculators cover the questions people ask most:
Percent of a number
To find X% of a number, multiply the number by X and divide by 100. Example: 15% of 200 = 200 × 15 ÷ 100 = 30.
What percent one number is of another
Divide the part by the whole and multiply by 100. Example: 45 is 45 ÷ 180 × 100 = 25% of 180.
Percentage change
Subtract the old value from the new value, divide by the old value, and multiply by 100. Example: from 120 to 150 is (150 − 120) ÷ 120 × 100 = +25%.
Frequently asked questions
How do I calculate a percentage increase?
Subtract the original number from the new number, divide the result by the original number, then multiply by 100. A positive result is an increase; a negative result is a decrease.
How do I add a percentage to a price?
Multiply the price by (1 + percentage/100). For example, adding 8% tax to $50 is 50 × 1.08 = $54. Our discount & sales-tax calculator does this automatically.