What is X% of Y?
X ÷ 100 × YPercentage Calculator
Solve common percentage, ratio and percentage-change questions.
Common percentage calculations
X is what percent of Y?
X ÷ Y × 100%X is Y% of what?
X ÷ (Y ÷ 100)Percentage change from X to Y
(Y − X) ÷ |X| × 100%X increased by Y%
X × (1 + Y ÷ 100)X reduced by Y%
X × (1 − Y ÷ 100)Practical percentage examples
These are everyday situations where choosing the right percentage formula matters.
20% discount
A $500 item reduced by 20% costs $400.
Exam score
45 correct answers out of 60 is a score of 75%.
Revenue growth
Revenue rising from 80,000 to 92,000 is a 15% increase.
Add a service charge
Adding a 10% service charge to 200 produces a total of 220.
Find the original total
If 30 is 15% of a total, the original total is 200.
The percentage calculator solves three common questions: a percentage of a number, one value as a percentage of another, and percentage increase or decrease. It shows the result without requiring you to remember which value belongs in the numerator or denominator.
Calculate a sale discount, Measure price or revenue growth, Convert a score into a percentage, and Compare a new value with a baseline
Choose the calculation mode before entering values and keep units consistent. For percentage change, the original value is the baseline; reversing the old and new values produces a different result.