Marginal Revenue The table on the left shows that marginal revenue is the change in total revenue when quantity sold increases by 1 unit. When the quantity sold increases from 2 units to 3 units, for example, total revenue increases from $32 to $42 so marginal revenue, the change in total revenue, is $10. The figure on the right shows how we can break down the change in total revenue into two parts. When the firm lowers the price from $16 to $14, it sells one more unit and so there is a gain in revenue of $14, the price of that unit, but since to sell that additional unit the firm had to lower the price, it loses $2 on each of its two previous sales so there is a revenue loss of $4. Thus, marginal revenue is the revenue gain on new sales plus the revenue loss on previous sales.