The mark-up of a retailer represents the gross profit earned on a product, expressed as a percentage of the cost price. In simpler terms, it is the amount by which the retailer increases the cost price of a product in order to earn a profit.
For example, if a retailer buys a product for $50 and adds a markup of 25%, the selling price will be $62.50 ($50 + 25% of $50). The mark-up, in this case, is 25%.
The mark-up is not the same as net profit or gross profit. Gross profit is the difference between revenue and the cost of goods sold, while net profit is the profit earned after all expenses, including taxes and overheads, have been subtracted from revenue. Opening stock refers to the inventory a business has at the beginning of a period, while closing stock refers to the inventory at the end of the period.
In summary, mark-up is the percentage by which a retailer increases the cost price of a product to earn a profit, while gross profit, net profit, opening stock, and closing stock are different accounting concepts that are not directly related to mark-up.