Profit Margins
Gross Profit Margin
GPM = Gross Profit / Sales = (Sales - COGS) / Sales
Net Profit Margin
NPM = Net Income / Sales
GPM only considers COGS. NPM accounts for all expenses, including OpEx, IntEx and taxes.
High GPMs and lower NPMs can be caused by a company improving efficiencies in direct production costs i.e COGS while experiencing increased OpEx, IntEx or taxes.