Just good info for anyone looking: Margin Formula The formula for calculating retail margin is the sales price of an item minus COGS, divided by the sales price, multiplied by 100. If you sell an item at $20 and paid $10 to acquire it and sell it, your retail margin is $10 divided by $20, or 50 percent. Retail products have variable margins, even within the same store or department. Markup to Margin A key factor that influences the margins on retail products is the markup percentage the retailer applies to particular goods. Calculating markup is essentially the inverse of calculating retail margin. You subtract your COGS from your desired sales price in the same way, but then divide that amount by your COGS. If your target price is $20 and your COGS are $10, your markup is $10 divided by $10, or 100 percent. Thus, to achieve a 50 percent margin on an item that costs you $10, you need a 100 percent markup.