Calculate percentages, proportions and percentage changes — fast and free.
A percentage calculator helps you quickly solve common percentage problems: calculate a percentage value, determine the proportion of a number, or find the percentage change between two values. Percentage calculations are used constantly in everyday life — shopping (discounts), school, financial calculations and statistics.
X% of Y = (X / 100) × Y | X is what % of Y = (X / Y) × 100 | Percentage change = ((New − Old) / |Old|) × 100. These three basic formulas cover virtually all percentage problems.