Percentage Calculator

A percentage represents a fraction of 100. The word itself comes from the Latin "per centum," meaning "by the hundred." Percentages are used everywhere — from finance (interest rates, discounts) to statistics (probability, growth rates) to everyday life (tips, grades).

Finding a percentage of a number: Multiply the number by the percentage divided by 100. For example, 25% of 200 is 200 × 0.25 = 50.

Finding what percent one number is of another: Divide the part by the whole and multiply by 100. For example, 50 is what percent of 200? Answer: (50 ÷ 200) × 100 = 25%.

Percentage change: Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase; negative is a decrease. For example, from 100 to 150: ((150 − 100) ÷ 100) × 100 = +50%.