Percentage Calculator
Calculate any percentage instantly — find X% of a number, percentage change, or what percent one number is of another.
How to calculate Percentage
Percentages are fundamental to everyday mathematics, appearing in finance, health, science, and daily shopping. The word "percent" means per hundred — so 25% literally means 25 out of every 100.
To find a percentage of a number, multiply the total by the percentage and divide by 100. Finding 20% of $85 gives $85 × 20 ÷ 100 = $17. This applies to discounts, tips, tax, and commission.
To discover what percentage one number represents of another, divide the part by the whole and multiply by 100. If 30 students passed out of 40, the pass rate is 30 ÷ 40 × 100 = 75%.
Percentage change measures growth or decline: ((new − old) ÷ old) × 100. A product rising from $50 to $60 has increased by 20%.
Retailers use percentages for discounts. Banks quote interest rates as percentages. Medical tests express accuracy as percentages. Nutritional labels show daily values as percentages. Mastering this single calculation saves real time every day — whether calculating VAT, a pay rise, or comparing deals.