Percentage Calculator
Calculate percentages quickly: what is X% of Y, what percent is X of Y, and percentage increase or decrease between two numbers.
🔒 Runs 100% in your browser — nothing is uploaded
What is X% of a number?
= 30
X is what percent of Y?
= 15%
Percentage increase / decrease
= 25% ▲ increase
About the percentage calculator
Three everyday percentage calculations in one place: find a percentage of a number, work out what percentage one number is of another, and calculate the percentage increase or decrease between two values. Results update as you type, right in your browser.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 is (200 × 15) ÷ 100 = 30. The first calculator does this for you.
How do I work out what percentage one number is of another?
Divide the first number by the second and multiply by 100. For example, 30 is (30 ÷ 200) × 100 = 15% of 200.
How do I calculate a percentage increase or decrease?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase; a negative result is a decrease.