To calculate the dollar amount of markup, you subtract the total costs from the selling price. What can you then do to get the markup percentage? The markup percentage calculation is cost X markup percentage. Then add that to the original unit cost (to arrive at the sales price). For example, if a product costs $100, then the selling price with a 25% markup would be $125.
Markup refers to the difference between the selling price of a good/service and its cost (is the added price over the total cost of the good/service that provides the seller with a profit).