Percentage Calculator
Calculate percentages, percentage change, ratios and proportions with the formula shown for every result.
What is P% of a number?
Result = Number × P ÷ 100
A is what percent of B?
Result = A ÷ B × 100
Percent change
Change = (To − From) ÷ From × 100
How to use
Three calculations are available. Results update as you type.
1. "P% of a number": Result = Number × P ÷ 100. Example: 10% of 250 is 250 × 10 ÷ 100 = 25.
2. "A is what percent of B": Result = A ÷ B × 100. Example: 30 is 30 ÷ 120 × 100 = 25% of 120.
3. "Percent change": Change = (To − From) ÷ From × 100. Example: from 80 to 100 is (100 − 80) ÷ 80 × 100 = +25% (increase).
Notes
Calculations use decimal arithmetic to avoid floating-point errors. When the whole (B) or the starting value is zero, division is impossible and an error is shown. All calculations run entirely in your browser.
FAQ
What is the difference between a percentage and a percent change?
A percentage compares a part to a whole. A percent change compares the difference to the starting value: 100 is 125% of 80, and the change from 80 to 100 is +25%.
Can a result exceed 100%?
Yes, when the part is larger than the whole, or a value more than doubles.