Margin calculator does one simple thing - lets you calculate any of the main variables in the sales process - cost of goods sold (how much you paid for the stuff Markup Calculator · Margin and VAT · Sales Tax · Margin with discount. Calculate gross margin on a product cost and selling price including profit margin and mark up percentage. Given cost and selling price calculate profit margin, Profit Margin Calculator · Get a Widget for this Calculator · Margin Calculator Widget. The gross profit margin expresses your profits as a percentage of the total sales revenues generated. This percentage allows you to compare the profits of.