Percentage Calculator
Calculate percentages instantly — find X% of Y, what percent X is of Y, and percentage change.
How Percentages Work
A percentage is a way of expressing a number as a fraction of 100. The word "percent" comes from the Latin per centum, meaning "by the hundred." Percentages are used everywhere — from sales tax and discounts to exam scores, investment returns, and statistical data.
There are three fundamental percentage calculations: finding a percentage of a number (e.g., "What is 15% of 200?"), finding what percentage one number is of another (e.g., "30 is what percent of 200?"), and finding the original number when you know a percentage (e.g., "30 is 15% of what number?"). This calculator handles all three, plus percentage change between two values.