What is consumer surplus?

Consumer surplus is the difference between the maximum price a buyer is willing to pay and the actual market price, multiplied by quantity and halved (triangle area). It represents the net benefit buyers receive from a transaction.

What is producer surplus?

Producer surplus is the difference between the market price and the minimum price a seller is willing to accept, multiplied by quantity and halved. It represents the net benefit sellers receive from a transaction.

Why is the formula 0.5 × base × height?

With linear demand and supply curves, the surplus areas are right triangles on the price-quantity diagram. The area of a triangle is 0.5 × base × height, where quantity is the base and the price difference is the height.

What does total surplus represent?

Total surplus (also called total economic surplus or social welfare) is the sum of consumer and producer surplus. It measures the total benefit to society from all transactions in a market.

Can consumer surplus be negative?

No. If the market price exceeds the maximum willingness to pay, buyers simply will not purchase, so quantity traded is zero and consumer surplus is zero. This calculator will show an error if the market price is above the max WTP.

What if the market price equals the max willingness to pay?

If market price equals max WTP, consumer surplus is zero — buyers are indifferent between buying and not buying, capturing no net benefit.

Consumer Surplus Calculator

Name: Consumer Surplus Calculator
Availability: InStock
Author: Nham Vu

Enter max willingness to pay, market price, min supply price, and quantity to calculate consumer surplus, producer surplus, and total surplus — with a live supply-demand chart.

Market Parameters

Max Willingness to Pay ($)

Highest price any buyer would pay (demand intercept)

Market Price ($)

Actual equilibrium price paid by buyers

Min Supply Price ($)

Lowest price any seller would accept (supply intercept)

Quantity Traded

Units bought and sold at equilibrium

Supply & Demand Diagram

Enter values above to see the diagram.

Summary

Enter max willingness to pay, market price, min supply price, and quantity to calculate consumer surplus, producer surplus, and total surplus — with a live supply-demand chart.

How it works

Enter the maximum willingness to pay — the highest price any buyer would accept.
Enter the current market price — the actual price buyers pay.
Enter the minimum supply price — the lowest price any seller would accept.
Enter the quantity traded at the market equilibrium.
Consumer surplus is calculated as 0.5 × (Max WTP − Market Price) × Quantity.
Producer surplus is calculated as 0.5 × (Market Price − Min Supply Price) × Quantity.
Total surplus is the sum of consumer and producer surplus.

Use cases

Economics students learning supply and demand concepts.
Checking homework answers for microeconomics assignments.
Visualizing how price changes affect consumer and producer welfare.
Analyzing the distributional effects of price floors and ceilings.
Understanding economic efficiency and deadweight loss concepts.
Business analysts estimating value captured by buyers versus sellers.

Frequently Asked Questions

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Last updated: 2026-05-23 · Reviewed by Nham Vu