What Is Price Elasticity of Demand?
Price elasticity of demand (PED) measures how much the quantity customers buy changes when a product’s price changes. For Shopify merchants, it helps estimate whether a price adjustment could increase revenue—and whether the change still makes sense after product costs.
PED is a local estimate based on the prices and sales volumes you compare; it does not guarantee how customers will respond to a future price. This calculator compares two price-and-quantity scenarios, so it can show which of those scenarios produces more revenue or profit, but it cannot prove a single price is the global revenue maximum.
Price Elasticity Formulas
The midpoint method uses the average of the old and new values as the base for each percentage change:
% Change in Quantity =
(New Quantity − Old Quantity) ÷ ((New Quantity + Old Quantity) ÷ 2)
% Change in Price =
(New Price − Old Price) ÷ ((New Price + Old Price) ÷ 2)
PED =
% Change in Quantity ÷ % Change in Price
Price and quantity usually move in opposite directions, so the signed PED is often negative. Merchants commonly classify demand using its absolute value, written as |PED|.
Revenue = Price × Quantity
Estimated Profit =
(Price − Product Cost) × Quantity
Here, product cost should represent the per-unit costs included in your estimate. The profit comparison is only as complete as those costs: fixed overhead, taxes, and expenses not entered separately are not included.
How to Use This Calculator
- Old Price — enter the original price before the change.
- New Price — enter the price you want to test or evaluate.
- Old Quantity — enter units sold per month at the original price.
- New Quantity — enter actual or estimated monthly units at the new price. Use comparable periods where possible.
- Product Cost — enter the total per-unit cost, including COGS, shipping, and fees, to compare estimated profit as well as revenue.
Use Shopify Analytics to gather sales quantities for periods with similar seasonality and marketing conditions. If you are planning a price change rather than analyzing a completed one, treat the new quantity as an estimate and test more than one plausible demand response.
Step-by-Step Example
Suppose a Shopify store changes the price of a ceramic planter from $40.00 to $36.00. Monthly sales rise from 80 to 92 units, and the estimated product cost is $14.00 per unit.
| Calculation | Result |
|---|---|
| Quantity change | (92 − 80) ÷ 86 = 13.95% |
| Price change | ($36 − $40) ÷ $38 = −10.53% |
| PED | 13.95% ÷ −10.53% = −1.33 |
| Revenue before | $40 × 80 = $3,200 |
| Revenue after | $36 × 92 = $3,312 |
| Estimated profit before | ($40 − $14) × 80 = $2,080 |
| Estimated profit after | ($36 − $14) × 92 = $2,024 |
The absolute PED is 1.33, indicating elastic demand in this comparison. Revenue increased by $112, but estimated profit fell by $56. The discount attracted enough extra orders to raise sales revenue, but not enough to offset the lower contribution per planter.
How to Interpret Elasticity When Setting Prices
| Absolute PED | Demand pattern | What the result suggests |
|---|---|---|
| Greater than 1 | Elastic | Quantity changes proportionally more than price; a price cut may raise revenue, but check profit. |
| Equal to 1 | Unit elastic | Quantity and price change by similar percentages; revenue is roughly unchanged in a small comparison. |
| Less than 1 | Inelastic | Quantity changes proportionally less than price; a price increase may raise revenue, subject to customer response and costs. |
These are classification thresholds, not universal industry averages. Necessities, differentiated products, and items with few close substitutes may be less price-sensitive; discretionary products with many comparable alternatives may be more sensitive. These are tendencies, not fixed rules. OpenStax’s economics text explains the relationship between elasticity and changes in quantity demanded.
A two-point comparison is not a controlled experiment: seasonality, promotions, ad spend, stock availability, and competitor activity can also change sales. For a better pricing decision, compare similar periods, monitor conversion rate and average order value, and test a sequence of prices rather than assuming one observed response applies at every price. The SBA’s market research guidance recommends examining customers and competitors as part of business planning.
7 Tips to Test Price Changes
- Change one product’s price at a time so you can separate its sales response from changes elsewhere in your catalog.
- Compare equal-length periods and check Shopify Analytics for unusual traffic or order changes before attributing a sales shift to price.
- Keep promotion conditions consistent; a coupon or free-shipping offer changes the effective price customers pay.
- Test a smaller price step first, such as a 3% adjustment, before trying a larger change that could make the result harder to interpret.
- Segment repeat and first-time buyers in your analysis; returning customers and new shoppers may respond differently to the same price.
- Include payment and fulfillment costs in Product Cost estimates, then use the Profit Margin Calculator to review broader margin effects.
- Compare a discount with a bundle; the Bundle Pricing Calculator can help assess whether a multi-item offer preserves contribution per order.
- Check the displayed reference price before promoting a sale; the FTC’s Guides Against Deceptive Pricing describe requirements around former-price comparisons.
Frequently Asked Questions
What is price elasticity of demand?
Price elasticity of demand (PED) measures how sensitive customer demand is to price changes. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. A PED greater than 1 in absolute value means demand is elastic, while a value below 1 means demand is inelastic.
How do you calculate price elasticity?
This calculator uses the midpoint method: PED = (% Change in Quantity) ÷ (% Change in Price), with each percentage change based on the average of the old and new values. To calculate it by hand, first find the quantity difference and divide it by average quantity, then find the price difference and divide it by average price, and finally divide the quantity percentage change by the price percentage change.
What is elastic vs. inelastic demand?
Elastic demand (|PED| > 1) means customers are relatively price-sensitive: a percentage price change is associated with a larger percentage change in quantity. Inelastic demand (|PED| < 1) means quantity changes proportionally less; luxury goods and products with many substitutes may be more elastic, while necessities or highly differentiated products may be less elastic.
Should I raise or lower my price based on elasticity?
If demand is inelastic, a price increase may raise revenue because the percentage drop in sales volume is smaller than the percentage price increase; if demand is elastic, a price decrease may raise revenue by increasing volume. Neither result guarantees higher profit, so compare contribution after product costs and account for costs that vary with price or order volume.
How do I find my product's price elasticity on Shopify?
Run a price test, then compare units sold before and after using Shopify Analytics and enter both periods in the calculator. For a more reliable comparison, test one product at a time, use periods of similar length, and keep marketing spend and promotions as consistent as possible.
About This Calculator
The Price Elasticity Calculator was built by Luis Dev Studio for Shopify merchants comparing price, demand, revenue, and estimated profit. Explore our Shopify services or contact us for help with your store’s pricing tools.
Updated by Luis Gonzalez · May 31, 2026