Price Elasticity of Demand
Calculate price elasticity of demand using the midpoint formula. Classify demand as elastic, inelastic, or unit elastic with revenue impact and charts.
About This Calculator
The Price Elasticity of Demand (PED) Calculator helps businesses, students, and economists measure how responsive consumer demand is to price changes. Using the midpoint (arc elasticity) formula, this calculator accurately determines whether a product has elastic, inelastic, or unit elastic demand, and shows the resulting impact on total revenue.
The midpoint formula calculates PED as: PED = ((Q1 - Q0) / ((Q1 + Q0) / 2)) / ((P1 - P0) / ((P1 + P0) / 2)), where P0 and Q0 are initial price and quantity, and P1 and Q1 are final price and quantity. This formula is preferred because it gives the same elasticity value regardless of whether price rises or falls, making it more reliable than the simple percentage method. The result is always negative due to the inverse relationship between price and demand — the absolute value is used for classification.
Elastic demand (|PED| > 1) means quantity changes proportionally more than price — luxury goods and products with substitutes fall here. Inelastic demand (|PED| < 1) means quantity changes proportionally less than price — necessities like food, medicine, and fuel. Unit elastic demand (|PED| = 1) is the theoretical midpoint where total revenue stays constant. The calculator also computes initial and final revenue, revenue change, and percentage changes in both price and quantity.
Regional Notes
India: The PED for essential goods like food grains, cooking oil, and medicines is typically inelastic (0.2–0.5) due to their necessity. Luxury goods and electronics show higher elasticity. The GST system groups goods by elasticity for tax rate assignment.
United States: Gasoline demand is highly inelastic in the short run (0.1–0.3) but more elastic over longer periods. Healthcare services and prescription drugs show very low elasticity. Consumer electronics and restaurant meals are typically elastic with PED values of 1.5–3.0.
United Kingdom: Fuel duty and VAT adjustments use elasticity analysis to predict revenue impacts. UK supermarket price wars leverage elastic demand for non-essential items. Alcohol and tobacco show relatively inelastic demand (0.3–0.7) due to habitual consumption.
Frequently Asked Questions
What is price elasticity of demand?
Price elasticity of demand (PED) measures how responsive the quantity demanded of a good is to a change in its price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price using the midpoint formula. A PED greater than 1 in absolute value indicates elastic demand, less than 1 indicates inelastic demand, and exactly 1 indicates unit elastic demand.
How do you calculate price elasticity of demand using the midpoint formula?
The midpoint formula for price elasticity of demand is: PED = (Q1 - Q0) / ((Q1 + Q0) / 2) / (P1 - P0) / ((P1 + P0) / 2), where P0 and Q0 are the initial price and quantity, and P1 and Q1 are the final price and quantity. This method gives the same elasticity value regardless of direction of change, making it more reliable than the simple percentage method.
What does elastic demand mean?
Elastic demand (PED > 1 in absolute value) means that the quantity demanded changes by a larger percentage than the price change. For elastic goods, a price decrease leads to higher total revenue, while a price increase reduces total revenue. Luxury goods, non-essential items, and products with many substitutes typically have elastic demand.
What does inelastic demand mean?
Inelastic demand (PED less than 1 in absolute value) means quantity demanded changes by a smaller percentage than the price change. For inelastic goods, a price increase leads to higher total revenue, while a price decrease reduces total revenue. Necessities like food, medicine, fuel, and utilities typically have inelastic demand.
What is unit elastic demand?
Unit elastic demand (PED = -1 in absolute value) means the percentage change in quantity demanded exactly equals the percentage change in price. When demand is unit elastic, total revenue remains unchanged when the price changes. This is a theoretical boundary between elastic and inelastic demand.
How does price elasticity affect business pricing strategy?
Businesses use price elasticity to set optimal prices. For products with elastic demand, lowering prices can increase total revenue. For products with inelastic demand, raising prices increases revenue. Businesses should price elastic goods competitively and can charge premium prices for inelastic necessities. Understanding PED helps maximize revenue and profit.
Is price elasticity of demand always negative?
Yes, price elasticity of demand is almost always negative because price and quantity demanded move in opposite directions according to the law of demand. When price increases, quantity demanded decreases, and vice versa. The negative sign is typically ignored in interpretation and the absolute value is used to classify elasticity as elastic, inelastic, or unit elastic.
What factors determine price elasticity of demand?
Key factors include: availability of substitutes (more substitutes = more elastic), necessity vs luxury (necessities are inelastic), proportion of income (higher cost goods are more elastic), time horizon (demand is more elastic in the long run), and brand loyalty (stronger loyalty = more inelastic). These factors vary across countries and markets including India, the US, and the UK.