Price Elasticity of Demand Calculator
Enter the old and new price, plus old and new quantity demanded. This tool uses the midpoint (arc elasticity) formula.
What is the price elasticity of demand?
Price elasticity of demand (PED) measures how sensitive customer demand is when price changes. In plain English: if you raise or lower price, how much does quantity demanded move?
PED is one of the most practical economics metrics for business owners, product managers, marketers, and students because it helps predict revenue impact before changing prices.
Midpoint formula used in this calculator
This midpoint method is preferred when comparing two real price points because it avoids getting different elasticity values depending on direction (price up versus price down).
How to use this calculator
- Enter the initial and new price.
- Enter the initial and new quantity demanded.
- Click Calculate Elasticity.
- Read the signed PED, absolute PED, interpretation, and revenue implication.
How to interpret your result
1) Elastic demand (|PED| > 1)
Quantity is very responsive to price changes. A small price increase can cause a relatively large drop in quantity demanded.
2) Inelastic demand (|PED| < 1)
Quantity is less responsive to price changes. Customers keep buying even when price changes. Essentials often fall in this range.
3) Unit elastic demand (|PED| ≈ 1)
Percentage change in quantity is about equal to percentage change in price. Revenue tends to stay roughly constant around that range.
Why businesses care about PED
If you know elasticity, pricing becomes less guesswork. You can test scenarios such as:
- Should we raise prices to improve margins?
- Will a discount campaign actually increase total revenue?
- Which products are more price sensitive than others?
- How should we price premium vs. value product lines?
Quick practical example
Suppose price rises from $10 to $12 and quantity falls from 100 to 85. The calculator returns an absolute PED above 1, which indicates elastic demand. That means the quantity drop is proportionally bigger than the price increase, so total revenue is likely to fall.
In that case, blindly increasing price may hurt sales and revenue. A better approach might be: improve product differentiation, bundle services, or use targeted pricing for less sensitive segments.
Common mistakes when calculating elasticity
- Using raw changes instead of percentage changes. PED must compare percentage movement.
- Ignoring sign convention. Demand curves are usually downward sloping, so signed PED is often negative.
- Comparing unrelated periods. Use intervals with stable market conditions when possible.
- Assuming one PED applies everywhere. Elasticity can change by price range, customer segment, and season.
FAQ
Should I use the negative sign?
Keep the signed value for technical work, but most business decisions classify elasticity using the absolute value.
What if the calculator gives a positive PED?
That can happen with unusual goods, data issues, or when other factors changed at the same time (promotion, income shifts, stockouts, competitors, seasonality). Treat it as a signal to review your data.
Is this the same as point elasticity?
Not exactly. This tool uses arc (midpoint) elasticity between two points. Point elasticity is based on a single point and derivative-based models.
Final takeaway
A reliable price elasticity of demand calculator helps you connect economics to real pricing decisions. Use it alongside market context, competitor behavior, and customer research for better outcomes.