Percentage Calculator
Fill in the numbers — answers update as you type.
What is X% of Y?
X is what % of Y?
% change from X to Y
How percentage calculations work
Finding X% of a number
Multiply the number by the percentage divided by 100. result = value × (percent ÷ 100)
Example: 15% of 200 = 200 × 0.15 = 30.
Finding what percent one number is of another
Divide the part by the whole, then multiply by 100. percent = (part ÷ whole) × 100
Example: 30 is what percent of 200? 30 ÷ 200 × 100 = 15%.
Percentage change between two numbers
Subtract the original from the new value, divide by the original, then multiply by 100. Positive means increase, negative means decrease. change = ((new − old) ÷ old) × 100
Example: from 200 to 250 → (250 − 200) ÷ 200 × 100 = +25%.
Frequently asked questions
Can I enter decimals?
Yes. Both whole numbers and decimals work. You can use a period (.) or a comma (,) as the decimal separator.
Are the results rounded?
Results are rounded to a maximum of 6 decimal places. Most everyday calculations only need 2.
Do you store the numbers I enter?
No. Every calculation happens in your browser. Nothing is sent to a server.
What's the difference between “X% of Y” and “X is what % of Y”?
The first asks for an absolute amount (15% of 200 = 30). The second asks for the ratio between two numbers as a percentage (30 out of 200 = 15%). Different questions, same arithmetic flipped around.