Percentage Calculator
Every percentage question, answered at once.
How it works
Percent means "per hundred", so every percentage question is the same division wearing a different hat.
Two of these are routinely confused. Percentage change measures from a starting value and is directional — 45 to 180 is +300%, but 180 to 45 is -75%. Percentage difference measures against the average of the two and is symmetric. Use change for before-and-after, difference for comparing two independent things.
Common questions
Why isn't a 50% rise cancelled by a 50% fall?
Because they apply to different bases. 100 up 50% is 150; 150 down 50% is 75. Reversing a 50% rise takes a 33.3% fall.
Related calculators
Discount CalculatorFinal price after one or two discounts, and what you save.Markup & Margin CalculatorConvert between markup and margin — they are not the same number.Sales Tax CalculatorAdd tax to a net price, or strip it out of a gross one.Ratio CalculatorSimplify ratios, scale them, and solve for a missing term.