While some investors are already well versed in financial metrics (hat tip), this article is for those who would like to learn about Return On Equity (ROE) and why it is important. To keep the lesson grounded in practicality, we'll use ROE to better understand Spirit AeroSystems Holdings, Inc. (NYSE:SPR).

Over the last twelve months Spirit AeroSystems Holdings has recorded a ROE of 46%. Another way to think of that is that for every $1 worth of equity in the company, it was able to earn $0.46.

View our latest analysis for Spirit AeroSystems Holdings

How Do You Calculate ROE?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Spirit AeroSystems Holdings:

46% = US$677m ÷ US$1.5b (Based on the trailing twelve months to June 2019.)

Most readers would understand what net profit is, but it’s worth explaining the concept of shareholders’ equity. It is all the money paid into the company from shareholders, plus any earnings retained. The easiest way to calculate shareholders' equity is to subtract the company's total liabilities from the total assets.

What Does ROE Mean?

ROE measures a company's profitability against the profit it retains, and any outside investments. 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 Spirit AeroSystems Holdings 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. As you can see in the graphic below, Spirit AeroSystems Holdings has a higher ROE than the average (15%) in the Aerospace & Defense industry.

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

The Importance Of Debt To Return On Equity

Companies usually need to invest money to grow their profits. That cash can come from retained earnings, issuing new shares (equity), or debt. In the first two cases, the ROE will capture this use of capital to grow. In the latter case, the debt used for growth will improve returns, but won't affect the total equity. That will make the ROE look better than if no debt was used.

Spirit AeroSystems Holdings's Debt And Its 46% ROE

Spirit AeroSystems Holdings does use a significant amount of debt to increase returns. It has a debt to equity ratio of 1.43. I think the ROE is impressive, but it would have been assisted by the use of debt. Investors should think carefully about how a company might perform if it was unable to borrow so easily, because credit markets do change over time.

In Summary

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. All else being equal, a higher ROE is better.

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 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.

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.