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. By way of learning-by-doing, we'll look at ROE to gain a better understanding of Atlantic Power Corporation (TSE:ATP).

Atlantic Power has a ROE of 23%, based on the last twelve months. One way to conceptualize this, is that for each CA$1 of shareholders' equity it has, the company made CA$0.23 in profit.

View our latest analysis for Atlantic Power

How Do You Calculate Return On Equity?

The formula for ROE is:

Return on Equity = Net Profit (from continuing operations) ÷ Shareholders' Equity

Or for Atlantic Power:

23% = US$47m ÷ US$202m (Based on the trailing twelve months to September 2019.)

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 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. 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. Clearly, then, one can use ROE to compare different companies.

Does Atlantic Power Have A Good Return On Equity?

One simple way to determine if a company has a good return on equity is to compare it to the average for its industry. Importantly, this is far from a perfect measure, because companies differ significantly within the same industry classification. As you can see in the graphic below, Atlantic Power has a higher ROE than the average (3.2%) in the Renewable Energy industry.

That's clearly a positive. We think a high ROE, alone, is usually enough to justify further research into a company. 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 two cases, the ROE will capture this use of capital to grow. In the latter case, the debt required for growth will boost returns, but will not impact the shareholders' equity. In this manner the use of debt will boost ROE, even though the core economics of the business stay the same.

Atlantic Power's Debt And Its 23% ROE

It appears that Atlantic Power makes extensive use of debt to improve its returns, because it has a relatively high debt to equity ratio of 3.22. Its ROE is no doubt quite impressive, but it would probably be a lot lower without the use of significant leverage.

The Bottom Line On ROE

Return on equity is one way we can compare the business quality of different companies. In my book the highest quality companies have high return on equity, despite low debt. If two companies have the same ROE, then I would generally prefer the one with less debt.

But when a business is high quality, the market often bids it up to a price that reflects this. Profit growth rates, versus the expectations reflected in the price of the stock, are a particularly important to consider. So I think it may be worth checking this free report on analyst forecasts for the company.

Of course Atlantic Power may not be the best stock to buy. So you may wish to see this free collection of other companies that have 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.

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