Consumer Surplus (Linear Demand)

What is this formula?

Consumer Surplus for a Linear Demand Curve measures the economic benefit consumers receive when they are willing to pay more than the actual market price.

For a linear demand curve, consumer surplus is represented by the triangular area below the demand curve and above the market price.

When to use it

Use this formula when analyzing welfare, market efficiency, price changes, taxation effects, and consumer benefits in a competitive market.

Example

Maximum willingness-to-pay price:

Pmax = 50 USD

Market equilibrium price:

Pe = 30 USD

Market equilibrium quantity:

Qe = 1000 units

Formula:

CS = 0.5 × (Pmax − Pe) × Qe

Substitution:

CS = 0.5 × (50 − 30) × 1000

CS = 10000 USD

Result:

Consumers receive a total surplus of 10,000 USD from the market transaction.

Applications

- Welfare economics

- Market efficiency analysis

- Tax policy evaluation

- Price regulation studies

- Microeconomic education

Note

This formula assumes a linear demand curve and a single market price. In real markets, demand may be nonlinear, consumers may differ in preferences, and market conditions may change over time. The result should be interpreted as an estimated welfare measure under the linear demand assumption.