What this calculator does
The price elasticity of demand calculator helps you measure how sensitive customer demand is when price changes. In economics, this is one of the most useful metrics for pricing strategy, revenue planning, and market analysis.
This page uses the midpoint (arc elasticity) method, which is the preferred way to compare two price-quantity points because it avoids directional bias.
Formula used in this calculator
% change in quantity = (Q2 - Q1) / ((Q1 + Q2) / 2)
% change in price = (P2 - P1) / ((P1 + P2) / 2)
How to interpret the number
- |PED| > 1: Elastic demand (buyers are sensitive to price changes)
- |PED| = 1: Unitary elastic demand
- |PED| < 1: Inelastic demand (buyers are less sensitive)
- PED usually negative: Typical inverse price-demand relationship
How to use the calculator correctly
- Enter your original price and new price.
- Enter quantity demanded at each price level.
- Click Calculate PED.
- Review the elasticity coefficient and classification.
For reliable results, use consistent units. If quantity is monthly sales units, both quantity inputs should represent monthly sales units.
Worked example
Suppose a product price increases from $10 to $12, and quantity demanded falls from 200 to 170 units.
- Quantity percent change (midpoint): (170 - 200) / ((200 + 170) / 2) = -30 / 185 = -16.22%
- Price percent change (midpoint): (12 - 10) / ((10 + 12) / 2) = 2 / 11 = 18.18%
- PED = -16.22% / 18.18% = -0.89
Because |PED| is less than 1, demand is inelastic. In this range, demand changes proportionally less than price.
Why price elasticity matters
1) Better pricing decisions
If your demand is elastic, large price increases can reduce quantity sold so much that total revenue drops. If demand is inelastic, moderate price increases may raise total revenue.
2) Revenue forecasting
Elasticity is a practical input for projections. It helps estimate the likely demand impact before rolling out pricing changes.
3) Competitive strategy
Markets with many substitutes generally have more elastic demand. If your product is highly differentiated, demand tends to be less elastic.
Common mistakes to avoid
- Using different time periods for old and new quantity data.
- Mixing seasonal and non-seasonal comparisons without adjustment.
- Ignoring promotions, stockouts, or ad campaigns that affect demand independently of price.
- Confusing elasticity sign and magnitude. Managers often use absolute value for classification, but the sign still has economic meaning.
Quick FAQ
Is a negative PED normal?
Yes. Most goods follow the law of demand: when price rises, quantity demanded falls.
Can PED be positive?
It can, but that is unusual and may indicate special cases (for example, Giffen-like behavior, Veblen effects, or data issues).
Should I use point elasticity or arc elasticity?
If you are comparing two known points, arc elasticity (midpoint method) is generally the best choice and is exactly what this calculator applies.
Final takeaway
Use this calculate price elasticity of demand calculator whenever you evaluate a price change. It provides a fast, consistent elasticity estimate and practical interpretation you can use for product pricing, budgeting, and growth planning.