Calculate price elasticity of demand from price and quantity changes.
% Change in Quantity = ((New Quantity − Old Quantity) ÷ Old Quantity) × 100
% Change in Price = ((New Price − Old Price) ÷ Old Price) × 100
Elasticity = % Change in Quantity ÷ % Change in Price
|Elasticity| > 1: Elastic; < 1: Inelastic; = 1: Unit elastic.
Price elasticity of demand measures how much quantity demanded changes when price changes.
Divide the percentage change in quantity by the percentage change in price.
Demand is elastic: a 1% price increase leads to more than 1% drop in quantity demanded.