Calculate percentages, percentage changes, and find what percent a number represents.
What is X% of Y?
% of= —
X is what percent of Y?
is what % of= —
Percentage change from X to Y
→= —
What is a Percentage Calculator?
A percentage calculator helps you work with percentages quickly and accurately. Percentages are ratios expressed as a fraction of 100, and they appear everywhere — from sales discounts and tax rates to exam scores and financial returns.
This tool offers three modes: finding a percentage of a number, finding what percentage one number is of another, and calculating percentage increase or decrease between two values. Each mode solves a different real-world problem instantly.
How to Use
1Choose the calculation mode that matches your question.
2Enter the numbers in the input fields.
3Click Calculate to see the result instantly.
Formulas
1. X% of Y
Result = (X ÷ 100) × Y
Example: 15% of 200 = (15 ÷ 100) × 200 = 30
2. X is what % of Y
Result = (X ÷ Y) × 100
Example: 30 is what % of 200 = (30 ÷ 200) × 100 = 15%
3. % Change from X to Y
Result = ((Y − X) ÷ |X|) × 100
Positive = increase, Negative = decrease
Example: 80 → 100 = ((100−80) ÷ 80) × 100 = +25%
Frequently Asked Questions
Multiply the number by the percentage and divide by 100. For example, 20% of 150 = (150 × 20) ÷ 100 = 30. Use Mode 1 in this calculator.
Divide the part by the whole, then multiply by 100. Example: 30 is what percent of 150? → (30 ÷ 150) × 100 = 20%. Use Mode 2.
Subtract the old value from the new, divide by the old value, then multiply by 100. A positive result is an increase; a negative result is a decrease. Use Mode 3.
Yes. To find a 10% discount on $200, use Mode 1: 10% of 200 = $20 off. To find the tax amount on a price, use Mode 1 with the tax rate as the percentage.