Percentages explained with examples

Learn how percentage-of, discounts, tax and percentage change calculations differ.

What a percentage means

A percentage is a proportion expressed out of 100. Twenty percent means 20 out of every 100, or 0.20 as a decimal.

Percentage of a number

To find 20% of 150, multiply 150 by 20 and divide by 100. The Percentage Calculator performs that basic operation.

Percentage change

Percentage change compares a new value with an original value. The original value is the reference point, which is why reversing the inputs can change the result. See the Percentage Change Calculator.

Discounts and tax

A discount reduces a price, while a tax increases a price. A 20% discount is not the same operation as adding 20% tax. Use the dedicated Discount Calculator and Sales Tax Calculator when you want the calculation spelled out.