Profitability Ratios: Net Profit Margin, Return on Assets (ROA), Return on Equity (ROE)

The best measure of a company is its profitability, for without it, it cannot grow, and if it doesn't grow, then its stock will trend downward. Increasing profits are the best indication that a company can pay dividends and that the share price will trend upward. Creditors will loan money at a cheaper rate to a profitable company than to an unprofitable one; consequently, profitable companies can use leverage to increase stockholders' equity even more.

The common profitability measures compare profits with sales, assets, or equity: net profit margin, return on assets, and return on equity. Although most financial services publish these ratios for most companies, they can be calculated independently by using net profit and total revenue from the Income Statement of a company's financial report, and total assets and stockholders' equity from the Balance Sheet.

Note that since the Income Statement of a financial report shows the result from a time period, usually 1 year, whereas the Balance Sheet shows the state of a company at a particular time, usually at the end of the company's fiscal year, balance sheet totals, such as total assets and stockholders' equity, are averaged by adding the total at the beginning of the fiscal year to the total at the end, then dividing by 2. More accurate results, especially for highly seasonal businesses, can be obtained by averaging quarters or months.

Net Profit Margin

The net profit margin is equal to the net profit (aka net income) after taxes and excluding extraordinary items divided by total revenues.

Net Profit Margin Formula
Net Profit Margin =Net Profit after Taxes
Total Revenues

Example—Calculating the Net Profit Margin of Microsoft

For its fiscal year 2008, Microsoft (MSFT) earned net income of $17,681,000,000 on $60,420,000,000 of total revenue. Since net profit margin is a ratio, we don't have to worry about the last 6 zeros, so we find that:

Microsoft Net Profit Margin = 17,681 / 60,42029.26%

Microsoft's profit margin is much higher than for most other businesses, because it can charge high prices for its 2 monopoly products, Windows and Office.


Profit Trends Are Better Indicators of a Company's Financial Health

In trying to determine the financial health of a company, it is better to look at least 5 to 10 years of profit statements, because profits in a single year may be misleading. Why? The company may have had an exceptionally good or bad year, or the company may be using different accounting methods than its peers.

Under generally accepted accounting principles, companies are permitted to use various methods to estimate expenses or to calculate expenses, such as depreciation. One company may use accelerated depreciation, but another company may use straight-line depreciation, so even if 2 companies had the same revenue and expenses, their profitability may be different. By looking at several years, depreciation expenses will average out, since no company can depreciate more than the cost of an item. There are also additional accounting methods that companies can use that may yield different profits within a given year, but will tend to average out over 5 years or more.

Thus, observing the profitability trend is more informative than looking at the PE ratio for a specific quarter or for the year.

The future stock price will also be determined by whether that profitability is increasing, decreasing, or stagnant — something that can only be observed over several years. Trend analysis should also be used when comparing different companies in the same industry, to see how the profitability of the industry itself is evolving over time, and to compare it with the profit trends of other industries.

Return on Assets

The return on assets (ROA) (aka return on total assets, return on average assets, return on investment (ROI), is one of the most widely used profitability ratios because it is related to both profit margin and asset turnover, and shows the rate of return for both creditors and investors of the company. ROA shows how well a company controls its costs and utilizes its resources.

Return on Assets (ROA) Formula
Return on Assets= Net Profit Margin× Asset Turnover
=Net Profit
Total Revenue
×Total Revenue
Average Total Assets
=Net Profit
Average Total Assets

A better name for ROA is return on average assets, since it is more descriptive in how it is calculated.

So a company can have a high return on assets even if it has a low profit margin because it has a high asset turnover. Grocery stores are a good example of a business with low profit margins but high turnover.

Example—Calculating the Return on Assets of Microsoft for 2008

The following numbers are in millions and Microsoft's fiscal year ends in June. Numbers for profit margin and total revenue calculated in the previous example are used here.

Total Assets 2008 = $72,793

Total Assets 2007 = $63,171

MSFT Average Total Assets = (72,793 + 63,171) / 2 = 67,982

1. Return on Assets = Net Profit / Average Total Assets = 17,681 / 67,982 = 0.2601 = 26.01%

Now we calculate ROA differently using asset turnover:

Asset Turnover = 60,420 / 67,982 = 0.8888 = 88.88%

2. ROA = Net Profit Margin × Asset Turnover = 29.26% × 88.88%26.01%

As you can see, equations 1 and 2 yield the same result.

Another method of determining the return on investment is to divide operating income by average operating assets. Operating income is income earned, before taxes and interest, from operating the business, in contrast to earning income from investments. Operating assets are long-term assets, notably property, plant, and equipment.

Return on Investment=Operating Income
Average Operating Assets

Return on Equity

The return on equity (ROE), also known as return on investment (ROI), is the best measure of the return, since it is the product of the operating performance, asset turnover, and debt-equity management of the firm. If a firm can borrow money and use it to achieve a higher return than the cost of the debt, then the leveraging creates additional revenue that accrues to stockholders as increased equity.

Return on Equity =Net Profit
Average Stockholders' Equity

A better name for ROE is the return on average equity, since like ROA, it is more descriptive of how ROE is actually calculated.

The difference between ROI and ROE is that the return on investment is the return on what the company invests in property, plants, and equipment, and other factors of production, while the return on equity is the return on the amount invested by the investor, the return per dollar of equity.

The return on equity is also equal to the return on assets multiplied by the debt-equity management ratio (aka equity multiplier):

 Debt-Equity Management Ratio =Average Total Assets
Average Total Stockholders' Equity

ROE = ROA × Debt-Equity Management Ratio

This equation can be broken down further:

Return on Equity (ROE) Formula
ROE= Operating Performance   × Asset Turnover× Debt-Equity Management Ratio
=Net Profit
Total Revenue
×Total Revenue
Average Total Assets
×Average Total Assets
Average Stockholders' Equity
=Net Profit
Average Stockholders' Equity

The debt-equity management ratio is proportional to the amount of debt being used by the company, because assets equals a company's liabilities plus stockholders' equity; hence, this ratio shows the amount of leverage that the company is using, and the ROE shows how well management is using debt to increase returns for stockholders. However, using debt also entails risk, since interest must be paid even in bad economic times.

Example—Calculating the Return on Equity for Microsoft in 2008

2007 Total Stockholders' Equity = $31,097

2008 Total Stockholders' Equity = $36,286

2008 Average Total Stockholders' Equity = (36,286 + 31,097) / 2 = $33,691.50

2008 Net Profit = $17,681

Return on Equity = 17,681 / 33,691.50 = 0.5248 = 52.48%

Calculating the ROE using average total assets and the debt-equity management ratio yields the same results:

2008 Average Total Assets = $67,982

Debt-Equity Management Ratio = 67,982 / 33,691.50 = 2.0178

Return on Equity = ROA × Debt-Equity Management Ratio = 26.01% × 2.0178 = 0.5248 = 52.48%

(Note that average total assets and ROA were calculated in the prior examples.)