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One of the best investments we can make is in our own knowledge and skill set. With that in mind, this article will work through how we can use Return On Equity (ROE) to better understand a business. By way of learning-by-doing, we'll look at ROE to gain a better understanding of Iliad SA (EPA:ILD).

Over the last twelve months Iliad has recorded a ROE of 9.2%. Another way to think of that is that for every €1 worth of equity in the company, it was able to earn €0.092.

View our latest analysis for Iliad

How Do I Calculate Return On Equity?

The formula for return on equity is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Iliad:

9.2% = €323m ÷ €3.6b (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 ROE Signify?

ROE looks at the amount a company earns relative to the money it has kept within the business. The 'return' is the yearly profit. 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 Iliad 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 is clear from the image below, Iliad has a lower ROE than the average (18%) in the Telecom industry.

That certainly isn't ideal. We'd prefer see an ROE above the industry average, but it might not matter if the company is undervalued. Nonetheless, it could be useful to double-check if insiders have sold shares recently.

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 two cases, the ROE will capture this use of capital to grow. In the latter case, the debt required for growth will boost returns, but will not impact the shareholders' equity. In this manner the use of debt will boost ROE, even though the core economics of the business stay the same.

Combining Iliad's Debt And Its 9.2% Return On Equity

Iliad clearly uses a significant amount of debt to boost returns, as it has a debt to equity ratio of 1.15. Its ROE is quite good but, it would have probably been lower without the use of debt. Debt increases risk and reduces options for the company in the future, so you generally want to see some good returns from using it.

In Summary

Return on equity is useful for comparing the quality of different businesses. A company that can achieve a high return on equity without debt could be considered a high quality business. All else being equal, a higher ROE is better.

But ROE is just one piece of a bigger puzzle, since high quality businesses often trade on high multiples of earnings. It is important to consider other factors, such as future profit growth -- and how much investment is required going forward. So you might want to take a peek at this data-rich interactive graph of forecasts for the company.

If you would prefer check out another company -- one with potentially superior financials -- then do not miss this free list of interesting companies, that have HIGH return on equity 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.