To find a percentage of a number, multiply the number by the percentage and divide by 100. For example, 20% of 50 is (50 × 20) / 100 = 10. Our calculator does this instantly for any values you enter. Useful for calculating BMI changes with our BMI calculator or calorie needs with our BMR calculator.

Percentage change is calculated as ((New Value - Old Value) / Old Value) × 100. Positive results show increase, negative show decrease. For example, from 50 to 60 is ((60-50)/50) × 100 = 20% increase. Perfect for tracking weight loss progress or body measurements over time.

The basic formula is (Part / Whole) × 100 = Percentage. For example, if 15 out of 60 students passed, the percentage is (15/60) × 100 = 25%. Our calculator handles all percentage formulas automatically. You can also use our unit converter for related mathematical conversions.

To calculate a discount, multiply the original price by the discount percentage and divide by 100, then subtract from the original. For example, 30% off $100 is $100 - ($100 × 30 / 100) = $70. Use our percentage decrease calculator for instant results.

To find the original amount when you know the result after a percentage change, divide the result by (1 + percentage/100) for increases, or by (1 - percentage/100) for decreases. Our reverse percentage calculator makes this easy.

A percentage is a fraction out of 100 (e.g., 50% = 50/100). A percentile is a value below which a certain percentage of data falls (e.g., 90th percentile means 90% of values are below this point). This tool calculates percentages, not percentiles.