consumer surplus is equal to the difference
Consumer surplus (Graph illustrating consumer (red) and producer (blue) surpluses on a supply and demand chart) Consumer surplus or Consumer's surplus (or in the plural Consumers' surplus) is the difference between the price consumers are willing to pay (or reservation price) and the actual price. If someone is willing to pay more than the actual price, their benefit in a transaction is how much they saved when they didn't pay that price.