Free online percentage calculator with three common modes: find a percent of a number, find what percent one number is of another, and calculate the percent change between two numbers — great for discounts, tax, growth and completion rates.
Working out a sale price, a score's share, a growth rate, a tip or tax, or whether something rose or fell — percentages are the most-used everyday maths. Remember three directions: the part (original × discount%), the proportion (part ÷ whole × 100), and the change ((new − old) ÷ old × 100).
'30% off, then another 20%' is not 50% off! Discounts multiply, not add: pay 70%, then 80% of that = 56% of the original — a 44% total discount. Whenever you see 'extra X% off', multiply the remaining fractions; stacked discounts are always less than the sum.
To see how much this month grew over last, use (new − old) ÷ old × 100; for tax or a tip, multiply by (1 + percent). For shopping discounts, see our discount guide; for invoice tax, use the invoice tax calculator.
Use the 'what percent' mode: result = part ÷ whole × 100%. For example, 20 is about 13.3% of 150.
Use the 'percent change' mode: result = (new − old) ÷ old × 100%. Positive is an increase, negative a decrease.
Yes. Use 'percent of' for the discounted amount, or 'percent change' to see how much a price dropped.