Q	P	TR	MR
1	100	100	100
2	99	198	98
3	98	294	96
4	97	388	94
5	96	480	92
6	95	570	90
7	94	658	88
8	93	744	86

To the left is a simple table which illustrates marginal revenue calculations for a firm with a downward sloping demand curve. The column labeled Q gives output, the column labeled P gives price. Note that for the firm to increase sales, price must be reduced for all units sold.

The column labeled TR gives total revenue, calculated as P x Q. The column labeled MR is the added revenue for each added unit sold. Because the price is reduced on all units the added or marginal revenue is below the price in every case. When the firm decides to increase sales, revenue increases by the price of the added unit, and falls by the reduction in price of the units that would have been sold at the higher price.