Many investors are still learning about the various metrics that can be useful when analysing a stock. This article is for those who would like to learn about Return On Equity (ROE). To keep the lesson grounded in practicality, we'll use ROE to better understand CMS Energy Corporation (NYSE:CMS).

CMS Energy has a ROE of 14%, based on the last twelve months. One way to conceptualize this, is that for each $1 of shareholders' equity it has, the company made $0.14 in profit.

Check out our latest analysis for CMS Energy

How Do You Calculate ROE?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for CMS Energy:

14% = US$657m ÷ US$4.8b (Based on the trailing twelve months to December 2018.)

Most readers would understand what net profit is, but it’s worth explaining the concept of shareholders’ equity. It is all earnings retained by the company, plus any capital paid in by shareholders. Shareholders' equity can be calculated by subtracting the total liabilities of the company from the total assets of the company.

What Does Return On Equity Signify?

ROE looks at the amount a company earns relative to the money it has kept within the business. The 'return' is the profit over the last twelve months. That means that the higher the ROE, the more profitable the company is. So, all else equal, investors should like a high ROE. That means it can be interesting to compare the ROE of different companies.

Does CMS Energy Have A Good Return On Equity?

By comparing a company's ROE with its industry average, we can get a quick measure of how good it is. The limitation of this approach is that some companies are quite different from others, even within the same industry classification. As you can see in the graphic below, CMS Energy has a higher ROE than the average (10%) in the Integrated Utilities industry.

That's what I like to see. In my book, a high ROE almost always warrants a closer look. For example you might check if insiders are buying shares.

The Importance Of Debt To Return On Equity

Most companies need money -- from somewhere -- to grow their profits. The cash for investment can come from prior year profits (retained earnings), issuing new shares, or borrowing. In the first and second cases, the ROE will reflect this use of cash for investment in the business. In the latter case, the use of debt will improve the returns, but will not change the equity. In this manner the use of debt will boost ROE, even though the core economics of the business stay the same.

Combining CMS Energy's Debt And Its 14% Return On Equity

CMS Energy does use a significant amount of debt to increase returns. It has a debt to equity ratio of 2.46. Its ROE is quite good but, it would have probably been lower without the use of debt. Investors should think carefully about how a company might perform if it was unable to borrow so easily, because credit markets do change over time.

The Bottom Line On ROE

Return on equity is useful for comparing the quality of different businesses. In my book the highest quality companies have high return on equity, despite low debt. If two companies have the same ROE, then I would generally prefer the one with less debt.

But when a business is high quality, the market often bids it up to a price that reflects this. Profit growth rates, versus the expectations reflected in the price of the stock, are a particularly important to consider. So you might want to take a peek at this data-rich interactive graph of forecasts for the company.

Of course CMS Energy may not be the best stock to buy. So you may wish to see this free collection of other companies that have high ROE and low debt.

We aim to bring you long-term focused research analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material.

If you spot an error that warrants correction, please contact the editor at editorial-team@simplywallst.com. This article by Simply Wall St is general in nature. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. Simply Wall St has no position in the stocks mentioned. Thank you for reading.