Mathematics
How to Calculate Percentages
Percentages are used for discounts, grades, reports, price increases and statistics. Most percentage questions use one of three simple formulas.
Open the percentage calculatorFind a percent of a number
To find X% of a number, multiply the number by X and divide by 100.
Example: 15% of 200 = 200 × 15 / 100 = 30.
Calculate percentage change
Percentage change compares a new value with an old value: ((new − old) / old) × 100.
A positive result is an increase; a negative result is a decrease.
Frequently asked questions
How do I calculate 20% quickly?
Divide the number by 5. For example, 20% of 150 is 30.
Related calculator
Percentage Calculator
Free percentage calculator to find a percent of a number, calculate percentage change and see what percent one value is of another. Useful for finance, school, discounts, statistics and everyday calculations.
Use the calculator