Profit = (P – AC) × Q Profit is (P – AC) × Q, profit per barrel times the number of barrels produced. When the price is $50 and 8 barrels of oil are produced, profit is shown on the graph as the shaded area. Notice that the price is the height of point a, AC is the height of point b, so that the area (a – b) × Q is equal to profit or $194 = ($50 – $25.75) × 8.