marginal revenue and marginal cost definition
DEFINITION of 'Marginal Revenue-MR'. The increase in revenue that results from the sale of one additional unit of output. Marginal revenue is calculated by dividing the change in total revenue by the change in output quantity.
The marginal cost of the second unit is the difference between the total cost of the second unit and total cost of the first unit. The marginal cost of the 5th unit is $5. It is the difference between the total cost of the 6th unit and the total cost of the, 5th unit and so forth.