The ratio of net profits to revenues for a company or business segment - typically expressed as a percentage – that shows how much of each dollar earned by the company is translated into profits. Net margins can generally be calculated as:
Taobiz explains Net Margin
Net margins will vary from company to company, and certain ranges can be expected from industry to industry, as similar business constraints exist in each distinct industry. A company like Wal-Mart has made fortunes for its shareholders while operating on net margins less than 5% annually, while at the other end of the spectrum some technology companies can run on net margins of 15-20% or greater.
Most publicly traded companies will report their net margins both quarterly and in their annual reports. Companies that are able to expand their net margins over time will generally be rewarded with share price growth, as it leads directly to higher levels of profitability.