The return on sales (ROS) is derived from the ROE model reviewed here:
ROE = ROA FL = ROS ATO FL
Net income = Net income Assets = Net income Sales Assets
Stockholders Assets St. Equity Sales Assets St. Equity
equity Operating Investing Financing
The ROS is also known as the profit margin. Net income is the bottom line on the income statement, and of course sales revenue is the firstline item. So the PM is the last line as a percentage of the first line and therefore shows how much of every dollar of sales a company can report as profit. Improving a PM (increasing it) can result from cutting costs relative
to sales.
Just as there are modifications of the ROA ratio, there are modifications to the PM.They all come from substituting various subtotals on the income statement for the net income in the numerator of the PM ratio. Some variations are (working down from the top of the income
statement):
Gross PM rate = Gross PM = Sales Cost of sales
Sales Sales
EBITDA margin rate = EBITDA
Sales
Operating PM rate = Operating income
Sales
OR EBIT
Sales
Pretax margin rate = Income before income taxes
Sales
As mentioned before, these margin ratios concern the success of the companys operations. All of these margin ratios will actually show up inwhat is referred to as common-sized income statements (covered in Chapter 6), prepared from multistep income statements that include subtotals. Exhibit 2.9 shows the margin ratios for Dow Chemical.The margin ratios
do not become negative in 2001 until after interest is deducted.
Taken From : ESSENTIALS of Financial Analysis