Consumer surplus equals buyers’ willingness to pay for a good minus the amount they actually pay, and it measures the benefit buyers get from participating in a market. Consumer surplus can be found by computing the area below the demand curve and above the price.

Producer surplus equals the amount sellers are paid for their goods minus their costs of production, and it measures the benefit sellers get from participating in a market. Producer surplus can be found by computing the area below the price and above the supply curve.