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 Cigna Corporation (NYSE:CI).

Our data shows Cigna has a return on equity of 9.6% for the last year. Another way to think of that is that for every $1 worth of equity in the company, it was able to earn $0.10.

View our latest analysis for Cigna

How Do I Calculate Return On Equity?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Cigna:

9.6% = US$4.3b ÷ US$45b (Based on the trailing twelve months to September 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. Shareholders' equity can be calculated by subtracting the total liabilities of the company from the total assets of the company.

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 profit over the last twelve months. The higher the ROE, the more profit the company is making. 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 Cigna 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. However, this method is only useful as a rough check, because companies do differ quite a bit within the same industry classification. As shown in the graphic below, Cigna has a lower ROE than the average (13%) in the Healthcare industry classification.

That certainly isn't ideal. It is better when the ROE is above industry average, but a low one doesn't necessarily mean the business is overpriced. Nonetheless, it could be useful to double-check if insiders have sold shares recently.

How Does Debt Impact Return On Equity?

Virtually all companies need money to invest in the business, to grow profits. That cash can come from retained earnings, issuing new shares (equity), 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 used for growth will improve returns, but won't affect the total equity. Thus the use of debt can improve ROE, albeit along with extra risk in the case of stormy weather, metaphorically speaking.

Cigna's Debt And Its 9.6% ROE

While Cigna does have some debt, with debt to equity of just 0.86, we wouldn't say debt is excessive. I'm not impressed with its ROE, but the debt levels are not too high, indicating the business has decent prospects. Careful use of debt to boost returns is often very good for shareholders. However, it could reduce the company's ability to take advantage of future opportunities.

The Key Takeaway

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 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. 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.

But note: Cigna may not be the best stock to buy. So take a peek at this free list of interesting companies with high ROE 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.