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 Greentown Service Group Co. Ltd. (HKG:2869).

Our data shows Greentown Service Group has a return on equity of 19% for the last year. Another way to think of that is that for every HK$1 worth of equity in the company, it was able to earn HK$0.19.

See our latest analysis for Greentown Service Group

How Do You Calculate Return On Equity?

The formula for return on equity is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Greentown Service Group:

19% = CN¥488m ÷ CN¥2.5b (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 the capital paid in by shareholders, plus any retained earnings. The easiest way to calculate shareholders' equity is to subtract the company's total liabilities from the total assets.

What Does ROE Mean?

ROE looks at the amount a company earns relative to the money it has kept within the business. The 'return' is the yearly profit. That means that the higher the ROE, the more profitable the company is. So, all else being equal, a high ROE is better than a low one. That means ROE can be used to compare two businesses.

Does Greentown Service Group Have A Good Return On Equity?

Arguably the easiest way to assess company's ROE is to compare it with the average in its industry. 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, Greentown Service Group has a higher ROE than the average (9.3%) in the Commercial Services industry.

That is a good sign. We think a high ROE, alone, is usually enough to justify further research into a company. For example you might check if insiders are buying shares.

Why You Should Consider Debt When Looking At ROE

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 debt required for growth will boost returns, but will not impact the shareholders' equity. That will make the ROE look better than if no debt was used.

Combining Greentown Service Group's Debt And Its 19% Return On Equity

Although Greentown Service Group does use debt, its debt to equity ratio of 0.12 is still low. The fact that it achieved a fairly good ROE with only modest debt suggests the business might be worth putting on your watchlist. Judicious use of debt to improve returns can certainly be a good thing, although it does elevate risk slightly and reduce future optionality.

But It's Just One Metric

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. If two companies have the same ROE, then I would generally prefer the one with less debt.

Having said that, while ROE is a useful indicator of business quality, you'll have to look at a whole range of factors to determine the right price to buy a stock. 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 you might want to check this FREE visualization of analyst forecasts for the company.

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

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.

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. Thank you for reading.