Calculating percent markup is a business term used to determine the difference between an item’s cost and its price. Put simply, it’s a way to measure how much profit you, as the seller, make from selling a product or service. It’s calculated by taking the total cost of the item (the money you spend buying it) and dividing it by the price of the item (the money you get for selling). The result is then multiplied by 100 to convert it into a percentage – that percentage is your percentage markup. By applying this formula on an ongoing basis, you can ensure that your business stays profitable and successful.