Profit as a proportion of sales revenue . It can be expressed as a total (the percentage of sales revenue which is profit), or it can be calculated on a unit basis (profit as a percentage of the selling price). The margin is different from the mark-up as the margin is a percentage of price while the mark-up is profit as a percentage of cost.
Example 33. Worked example: a sofa is bought by a furniture shop for £500 and sold for £625