Percentage Calculator

Calculate percentages in multiple ways. Results update instantly.

What is X% of Y?

%
Result
30
15% of 200 = 30

X is what percent of Y?

Result
15%
30 is 15% of 200

Percentage Change (Increase/Decrease)

Percentage Change
+25%
An increase of 25% from 80 to 100

Percentage Difference Between Two Values

Percentage Difference
40%
The difference between 50 and 75 is 40%

How to Calculate Percentages

This calculator handles four common percentage calculations, each updating instantly as you type.

What is X% of Y?

Multiply the value by the percentage divided by 100. For example, 15% of 200 = 200 × 0.15 = 30. Useful for calculating tips, discounts, tax amounts, and more.

X is What Percent of Y?

Divide the part by the whole and multiply by 100. For example, 30 is what percent of 200? 30 ÷ 200 × 100 = 15%. Useful for test scores, completion rates, and proportions.

Percentage Change

Calculate how much a value has increased or decreased: ((New - Old) ÷ Old) × 100. A change from 80 to 100 is a 25% increase. A change from 100 to 80 is a 20% decrease. Useful for tracking prices, performance metrics, and growth.

Percentage Difference

Find the relative difference between two values: (|A - B| ÷ ((A + B) ÷ 2)) × 100. Unlike percentage change, this doesn't assume one value is "original" — it measures how different two values are from each other.

FAQ

Percentage change measures how much a value increased or decreased relative to the original. It has direction (positive = increase, negative = decrease). Percentage difference measures how far apart two values are relative to their average, regardless of which came first.
To calculate a discount, use "What is X% of Y?" where X is the discount percentage and Y is the original price. Subtract the result from the original price to get the sale price. For example, a 25% discount on $80: 25% of 80 = $20, so the sale price is $80 - $20 = $60.
Use "What is X% of Y?" where X is the tip percentage (typically 15-20%) and Y is the bill amount. For example, 18% of $45 = $8.10. Or use our dedicated tip calculator which also splits the bill.