Quick reference
Percent of a number: (percent ÷ 100) × number. E.g., 20% of 50 = 10.
What percent is X of Y: (X ÷ Y) × 100. E.g., 15 of 60 = 25%.
Percentage change: ((new − old) ÷ old) × 100. Positive = increase, negative = decrease.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage, then divide by 100. 20% of 50 = (20 × 50) ÷ 100 = 10.
How do I find what percent one number is of another?
Divide the part by the whole, then multiply by 100. 15 ÷ 60 × 100 = 25%.
How do I calculate percentage increase or decrease?
((new value − old value) ÷ old value) × 100. A positive result means an increase; negative means a decrease.