Price Elasticity
With price before 10 USD, price after 12 USD, units sold before 1000, units sold after 850, price elasticity comes to -0.892 — elasticity. It is reached in 6 steps, the last of which is -16.216216 / 18.181818, and each one is printed on the page with its numbers filled in. The formula is the one published by US Bureau of Labor Statistics, not an approximation fitted to it.
Price elasticity by the midpoint method, with what the price change does to revenue — the figure the elasticity exists to predict.
Formula and sources checked · How we check
Price before 10, Price after 12, Units sold before 1000, Units sold after 850
-0.892
Elasticity for the example below. Editing a field recomputes the calculator below; this figure holds the answer the page was loaded with.
It is written into the HTML rather than drawn by a script, so a search engine reading this page without running JavaScript still finds an answer.
- Change in quantity, midpoint method
(850 - 1000) / ((850 + 1000) / 2) * 100-16.216 %- Change in price, midpoint method
(12 - 10) / ((12 + 10) / 2) * 10018.182 %- Price elasticity of demand
-16.216216 / 18.181818-0.892- Revenue before
10 * 100010,000 USD- Revenue after
12 * 85010,200 USD- Change in revenue
10200 - 10000200 USD
Worked example
Raising the price from $10 to $12 lost 150 of 1,000 sales — an elasticity of −0.89, just inside inelastic. Revenue rose from $10,000 to $10,200. Had sales fallen to 800 instead, elasticity would be −1.22, revenue $9,600, and the rise a mistake.
How to work it out yourself
- 1.Use the midpoint method, which is what this computes. Dividing by the starting value gives a different elasticity depending on which direction you measure, and the midpoint form gives the same answer both ways.
- 2.Read the sign as a check, not as information. Demand elasticity is almost always negative because price and quantity move opposite ways; a positive figure means something else changed at the same time.
- 3.Compare the absolute value to 1. Below 1 is inelastic and a price rise raises revenue; above 1 is elastic and a price rise lowers it. That crossing point is the only thing the number is for.
- 4.Isolate the price change. Elasticity measured across a period when you also advertised, changed packaging, or hit a season is not measuring price.
Elasticity as the units sold after the rise vary
| Units sold after | Elasticity | Revenue after | Change in revenue |
|---|---|---|---|
| 500 | -3.667 | 6,000 USD | -4,000 USD |
| 600 | -2.750 | 7,200 USD | -2,800 USD |
| 700 | -1.941 | 8,400 USD | -1,600 USD |
| 800 | -1.222 | 9,600 USD | -400 USD |
| 850 | -0.892 | 10,200 USD | 200 USD |
| 900 | -0.579 | 10,800 USD | 800 USD |
| 950 | -0.282 | 11,400 USD | 1,400 USD |
| 1000 | 0.000 | 12,000 USD | 2,000 USD |
| 1050 | 0.268 | 12,600 USD | 2,600 USD |
| 1100 | 0.524 | 13,200 USD | 3,200 USD |
| 1200 | 1.000 | 14,400 USD | 4,400 USD |
Revenue turns where absolute elasticity passes 1. Below that the price rise wins; above it the lost volume costs more than the higher price brings in, and revenue falls despite charging more.
The formula
- Change in quantity, midpoint method
(850 - 1000) / ((850 + 1000) / 2) * 100 - Change in price, midpoint method
(12 - 10) / ((12 + 10) / 2) * 100 - Price elasticity of demand
-16.216216 / 18.181818 - Revenue before
10 * 1000 - Revenue after
12 * 850 - Change in revenue
10200 - 10000
Source: US Bureau of Labor Statistics — consumer expenditure and price response data, Federal Reserve Bank of St. Louis, FRED — price and quantity series for elasticity work, OECD — glossary of statistical terms, price elasticity of demand
Questions people actually ask
- What is price elasticity of demand?
- The percentage change in quantity demanded divided by the percentage change in price. An elasticity of −0.89 means a 1% price rise costs 0.89% of unit sales.
- What is the midpoint method and why use it?
- It divides each change by the average of the before and after values rather than by the starting one. Without it, a price rise from $10 to $12 and a fall from $12 to $10 give different elasticities for the same pair of points, which is plainly wrong.
- What does elastic and inelastic mean?
- Elastic is an absolute elasticity above 1: buyers are sensitive, and raising the price loses more volume than it gains in margin. Inelastic is below 1 — insulin, petrol, cigarettes — where a price rise raises revenue. Exactly 1 is unit elastic, and revenue does not move.
- How do I use elasticity to set a price?
- If demand is inelastic you are leaving money on the table; if it is elastic, raising the price shrinks revenue. Note that revenue is not profit — with elastic demand, a price rise can cut revenue while raising profit, because you are also selling fewer units to make.
- What makes demand elastic?
- Substitutes above all. One brand of soap is elastic because another sits beside it; soap in general is not. Necessity, the share of income a purchase takes, and how long buyers have to react all push the same way — elasticity is always higher over a longer horizon.
Related
- Margin and Markup CalculatorMargin and markup from cost and price — the two are not the same number, and the page shows both every time.
- Sales Tax CalculatorTax and total from a pre-tax price, plus the reverse — the pre-tax price hidden inside a total you already paid.
- PayPal Fee CalculatorWhat PayPal takes from a payment and what reaches you, on the US rates published 1 September 2026 — plus the amount to invoice to net a target figure.
- Net Worth CalculatorNet worth from what you own and what you owe, split into liquid and illiquid — with the months of expenses the liquid half would actually cover.
- Salary CalculatorPay converted between every period — hourly, daily, weekly, biweekly, semi-monthly, monthly and annual — with unpaid holidays and days off taken out.
- Tip CalculatorTip and total from a bill, and what each person owes once it is split — including the rounding that makes the split come out even.
Put this calculator on your site
Free, no attribution required beyond the link.
<iframe src="https://rulecalculators.com/embed/price-elasticity" width="100%" height="420" style="border:1px solid #e7e4de;border-radius:12px" title="Price Elasticity"></iframe>