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). We'll use ROE to examine Infrastrutture Wireless Italiane S.p.A. (BIT:INW), by way of a worked example.

Over the last twelve months Infrastrutture Wireless Italiane has recorded a ROE of 9.4%. Another way to think of that is that for every €1 worth of equity in the company, it was able to earn €0.094.

See our latest analysis for Infrastrutture Wireless Italiane

How Do I Calculate ROE?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Infrastrutture Wireless Italiane:

9.4% = €140m ÷ €1.5b (Based on the trailing twelve months to June 2019.)

It's easy to understand the 'net profit' part of that equation, but 'shareholders' equity' requires further explanation. It is all earnings retained by the company, plus any capital paid in by shareholders. The easiest way to calculate shareholders' equity is to subtract the company's total liabilities from the total assets.

What Does ROE Signify?

Return on Equity measures a company's profitability against the profit it has kept for the business (plus any capital injections). The 'return' is the profit over the last twelve months. The higher the ROE, the more profit the company is making. So, as a general rule, a high ROE is a good thing. That means it can be interesting to compare the ROE of different companies.

Does Infrastrutture Wireless Italiane Have A Good ROE?

One simple way to determine if a company has a good return on equity is to compare it to the average for its industry. However, this method is only useful as a rough check, because companies do differ quite a bit within the same industry classification. If you look at the image below, you can see Infrastrutture Wireless Italiane has a similar ROE to the average in the Telecom industry classification (11%).

That isn't amazing, but it is respectable. ROE tells us about the quality of the business, but it does not give us much of an idea if the share price is cheap. If you are like me, then you will not want to miss this free list of growing companies that insiders are buying.

How Does Debt Impact Return On Equity?

Most companies need money -- from somewhere -- to grow their profits. That cash can come from retained earnings, issuing new shares (equity), or debt. In the case of the first and second options, the ROE will reflect this use of cash, for growth. 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 Infrastrutture Wireless Italiane's Debt And Its 9.4% Return On Equity

Although Infrastrutture Wireless Italiane does use debt, its debt to equity ratio of 0.12 is still low. I'm not impressed with its ROE, but the debt levels are not too high, indicating the business has decent prospects. Careful use of debt to boost returns is often very good for shareholders. However, it could reduce the company's ability to take advantage of future opportunities.

But It's Just One Metric

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 around the same level of debt to equity, and one has a higher ROE, I'd generally prefer the one with higher ROE.

But ROE is just one piece of a bigger puzzle, since high quality businesses often trade on high multiples of earnings. The rate at which profits are likely to grow, relative to the expectations of profit growth reflected in the current price, must be considered, too. So I think it may be worth checking this free report on analyst forecasts for the company.

Of course, you might find a fantastic investment by looking elsewhere. So take a peek at this free list of interesting companies.

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.