Percentage of Number
Find what percentage one number is of another, or find a percentage of a number — all in your browser, instant results.
What is X% of Y?
X is what % of Y?
Percentage change from X to Y
About the Percentage Calculator
This percentage calculator runs entirely in your browser. It supports three common calculations: finding a percentage of a number, finding what percentage one number is of another, and computing the percentage change between two numbers. All calculations update live as you type.
Formulas used
- X% of Y = (X / 100) × Y
- X is what % of Y = (X / Y) × 100
- Percentage change from X to Y = ((Y − X) / X) × 100
Frequently asked questions
Does this tool upload my data? No. All calculations happen locally in your browser. Your inputs never leave your device.
Can I use decimals? Yes. All inputs accept decimals and negative numbers where mathematically meaningful.
What does a negative percentage change mean? A negative result indicates a decrease from the original value to the new value.
Why does the calculator show an error when Y is 0? Dividing by zero is undefined in mathematics. The calculator shows "—" to indicate the result is not computable.