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 National Grid plc (LON:NG.).

Return on Equity or ROE is a test of how effectively a company is growing its value and managing investors’ money. Put another way, it reveals the company's success at turning shareholder investments into profits.

View our latest analysis for National Grid

How To Calculate Return On Equity?

The formula for return on equity is:

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

So, based on the above formula, the ROE for National Grid is:

4.8% = UK£1.7b ÷ UK£36b (Based on the trailing twelve months to September 2024).

The 'return' is the amount earned after tax over the last twelve months. That means that for every £1 worth of shareholders' equity, the company generated £0.05 in profit.

Does National Grid 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. Importantly, this is far from a perfect measure, because companies differ significantly within the same industry classification. As shown in the graphic below, National Grid has a lower ROE than the average (11%) in the Integrated Utilities industry classification.

Unfortunately, that's sub-optimal. Although, we think that a lower ROE could still mean that a company has the opportunity to better its returns with the use of leverage, provided its existing debt levels are low. A company with high debt levels and low ROE is a combination we like to avoid given the risk involved. To know the 4 risks we have identified for National Grid visit our risks dashboard for free.

How Does Debt Impact ROE?

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. Thus the use of debt can improve ROE, albeit along with extra risk in the case of stormy weather, metaphorically speaking.

National Grid's Debt And Its 4.8% ROE

It's worth noting the high use of debt by National Grid, leading to its debt to equity ratio of 1.30. The combination of a rather low ROE and significant use of debt is not particularly appealing. Debt increases risk and reduces options for the company in the future, so you generally want to see some good returns from using it.

Conclusion

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. 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. 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 check this FREE visualization of analyst forecasts for the company.

Of course National Grid 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.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.