Markup refers to the percentage of an item's cost that a retailer adds when reselling it to customers. The higher the markup, the more the retailer will profit. In order to calculate the amount of a markup, you need to know the retail price and actual cost of the item. The markup is usually reported as a percentage.
Things You Will Need
Item retail price
Determine the cost to produce or acquire the product that you are selling. For example, if you are determining the markup for a table, you may check your purchase invoice to see that it cost you $300 to buy wholesale.
Divide the selling price of the item by the cost of the item. For example, if you sold the table for $330 and you bought it for $300, you would divide $330 by $300 to get "1.1."
Subtract "1" from the result in the step above to calculate the markup expressed as a decimal. Continuing the example, you would subtract "1" from "1.1" to get "0.1."
Multiply the markup expressed as a decimal by 100 to change the markup to a percent. Finishing this example, you would multiply "0.1" by 100 to get 10 percent, which is the amount of your markup.