Understanding Consumer Surplus

This lesson explores Consumer Surplus: the difference between the maximum price a consumer is willing to pay and the price they actually pay. The graph shows a linear demand curve, P = 20 − 2Q, where Price sits on the vertical axis and Quantity on the horizontal axis.

The graph breaks down total consumer surplus into the consumer surplus for each unit. The amount of consumer surplus for each unit is labeled directly on the graph, so you can see how it changes when the market price changes and how additional units may generate consumer surplus.

How to Use the Playground

• Use the slider or +/− buttons (on mobile) to change the Price.
• Watch the Consumer Surplus area change as the price changes.
• The Base and Height values are shown for reference and update automatically.
• Use the displayed Base and Height values to see how they determine the size of the consumer surplus.