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. To keep the lesson grounded in practicality, we'll use ROE to better understand Dollar Industries Limited (NSE:DOLLAR).

Dollar Industries has a ROE of 18%, based on the last twelve months. One way to conceptualize this, is that for each ₹1 of shareholders' equity it has, the company made ₹0.18 in profit.

Check out our latest analysis for Dollar Industries

How Do You Calculate Return On Equity?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Dollar Industries:

18% = ₹736m ÷ ₹4.2b (Based on the trailing twelve months to March 2019.)

Most know that net profit is the total earnings after all expenses, but the concept of shareholders' equity is a little more complicated. It is the capital paid in by shareholders, plus any retained earnings. 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 Mean?

ROE measures a company's profitability against the profit it retains, and any outside investments. The 'return' is the profit over the last twelve months. A higher profit will lead to a higher ROE. 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 Dollar Industries 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. The limitation of this approach is that some companies are quite different from others, even within the same industry classification. Pleasingly, Dollar Industries has a superior ROE than the average (7.9%) company in the Luxury industry.

That's clearly a positive. In my book, a high ROE almost always warrants a closer look. One data point to check is if insiders have bought shares recently.

How Does Debt Impact ROE?

Virtually all companies need money to invest in the business, to grow profits. That cash can come from issuing shares, retained earnings, or debt. In the first and second cases, the ROE will reflect this use of cash for investment in the business. 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 Dollar Industries's Debt And Its 18% Return On Equity

While Dollar Industries does have some debt, with debt to equity of just 0.54, we wouldn't say debt is excessive. 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 one way we can compare the business quality of different companies. Companies that can achieve high returns on equity without too much debt are generally of good quality. 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 when a business is high quality, the market often bids it up to a price that reflects this. 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.

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.