Percentage Calculator
Three calculators in one: find X% of a number, work out what percentage one number is of another, and measure percentage increase or decrease.
What is X% of Y?
X is what % of Y?
Percentage increase / decrease
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Calculating Percent Difference and Profit Margins
Percent of a number is a simple multiplication: 15% of 240 is 240 × 0.15 = 36. To express one number as a percentage of another, divide and multiply by 100: 36 of 240 is (36 ÷ 240) × 100 = 15%.
Percentage change compares a new value with an original: ((new − old) ÷ old) × 100. A price moving from 80 to 100 is a 25% increase, but moving back from 100 to 80 is a 20% decrease — percentages are not symmetric, which is why discount stacking rarely returns you to the starting price.
Profit margin and markup are frequently confused. Margin is profit as a share of revenue: (revenue − cost) ÷ revenue. Markup is profit as a share of cost: (revenue − cost) ÷ cost. An item bought at 60 and sold at 100 carries a 40% margin but a 67% markup. Quote margins when talking to finance and markups when pricing against supplier costs.
Frequently asked questions
Use the “X% of Y” calculator to find the discount amount, then subtract it from the original price. A 25% discount on 120 is 30, giving a final price of 90.