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). By way of learning-by-doing, we'll look at ROE to gain a better understanding of Petards Group plc (LON:PEG).

Petards Group has a ROE of 14%, based on the last twelve months. That means that for every £1 worth of shareholders' equity, it generated £0.14 in profit.

View our latest analysis for Petards Group

How Do You Calculate Return On Equity?

The formula for return on equity is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Petards Group:

14% = UK£1.1m ÷ UK£8.1m (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?

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 amount earned after tax over the last twelve months. A higher profit will lead to a higher ROE. So, all else being equal, a high ROE is better than a low one. Clearly, then, one can use ROE to compare different companies.

Does Petards Group 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. However, this method is only useful as a rough check, because companies do differ quite a bit within the same industry classification. Pleasingly, Petards Group has a superior ROE than the average (9.2%) company in the Software industry.

That's what I like to see. I usually take a closer look when a company has a better ROE than industry peers. For example, I often check if insiders have been buying shares .

Why You Should Consider Debt When Looking At 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 use of debt will improve the returns, but will not change the equity. That will make the ROE look better than if no debt was used.

Petards Group's Debt And Its 14% ROE

Although Petards Group does use debt, its debt to equity ratio of 0.14 is still low. Its very respectable ROE, combined with only modest debt, suggests the business is in good shape. Conservative use of debt to boost returns is usually a good move for shareholders, though it does leave the company more exposed to interest rate rises.

But It's Just One Metric

Return on equity is one way we can compare the business quality of different companies. A company that can achieve a high return on equity without debt could be considered a high quality business. 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.

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. 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.

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.