ocr: Net Profit Margin A further aspect of protitability and one that impacts directly upon the ROCE: is the net profit margin of the business. This ratio tells us how much profit is earned for every Elofsales made by the business. The ratio is calculated as: PBIT x1 100% Sales) In our example PBIT l £378 and Sales - E6000 Hence, Net Profit Margin - (3200 )x100% 6.3% This tells us that the business makes - a profit of6.3p: per E1 ofs sales.