Percentage Calculator
Four common percentage calculations in one place — no sign-up, works instantly in your browser.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
Increase/decrease a number by a percentage
How to use this tool
Each of the four boxes above handles a different, commonly needed percentage calculation. Fill in the numbers and press "Calculate" — each box works independently.
About these calculations
X% of Y = (X / 100) × Y.
X is what percent of Y = (X / Y) × 100.
Percentage change from X to Y = ((Y − X) / X) × 100 — positive means an increase, negative means a decrease.
Increase/decrease a number by a percentage = Y × (1 + X/100).
Standard percentage arithmetic; results are exact for the numbers you enter (subject to normal floating-point display rounding).
Frequently asked questions
How do I calculate X% of Y?
Multiply Y by X and divide by 100: X% of Y = (X / 100) × Y. For example, 20% of 150 is (20/100) × 150 = 30.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100: (part / whole) × 100. For example, 30 is what percent of 150? (30/150) × 100 = 20%.
How is percentage change calculated?
Percentage change = ((new value − old value) / old value) × 100. A positive result is a percentage increase; a negative result is a percentage decrease.
What's the difference between percentage points and percent?
A percentage point is the simple arithmetic difference between two percentages (e.g. going from 40% to 50% is a 10 percentage point increase), while a percent change describes that same move relative to the starting value (a 25% increase, since 10 is 25% of 40). This tool's percentage-change mode computes the relative (percent) change, not percentage points.