Percentage Calculator
This percentage calculator covers three everyday calculations in one place: finding what X% of Y is, finding what percent X is of Y, and finding the percentage increase or decrease between two numbers. Each result updates instantly, so you can check a tip, a discount, or a year-over-year change without doing the arithmetic by hand. It runs entirely in your browser, with nothing sent to a server.
Frequently asked questions
How is percentage change calculated?
Percentage change is calculated as ((new value - old value) / old value) x 100 — a positive result means an increase, a negative result means a decrease.
How do I calculate what X% of Y is?
Multiply Y by X and divide by 100 — for example, 20% of 150 is (150 x 20) / 100 = 30, which is exactly what the "X% of Y" calculation returns.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100 — for example, to find what percent 30 is of 150, calculate (30 / 150) x 100 = 20%, which is what the "X as a % of Y" calculation returns.
What is the difference between percentage change and percentage points?
Percentage change measures relative change using the ((new - old) / old) x 100 formula — going from 20% to 30% is a 50% relative increase — while a percentage point difference is simple subtraction, so the same move from 20% to 30% is a 10 percentage point increase; mixing the two up is a common source of error when reading statistics.