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 Ambu A/S (CPH:AMBU B).

Over the last twelve months Ambu has recorded a ROE of 20%. That means that for every DKK1 worth of shareholders' equity, it generated DKK0.20 in profit.

Check out our latest analysis for Ambu

How Do I Calculate ROE?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Ambu:

20% = ø372m ÷ ø1.9b (Based on the trailing twelve months to December 2018.)

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. You can calculate shareholders' equity by subtracting the company's total liabilities from its total assets.

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 yearly profit. 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 it can be interesting to compare the ROE of different companies.

Does Ambu Have A Good ROE?

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. You can see in the graphic below that Ambu has an ROE that is fairly close to the average for the Medical Equipment industry (24%).

That's not overly surprising. ROE tells us about the quality of the business, but it does not give us much of an idea if the share price is cheap. For those who like to find winning investments this free list of growing companies with recent insider purchasing, could be just the ticket.

How Does Debt Impact Return On Equity?

Most companies need money -- from somewhere -- to grow their 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.

Combining Ambu's Debt And Its 20% Return On Equity

While Ambu does have some debt, with debt to equity of just 0.73, 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. 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.

But It's Just One Metric

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

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.

Of course, you might find a fantastic investment by looking elsewhere. So take a peek at this free list of interesting companies.

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.