Return On Equity - The Formula

The Formula

ROE is equal to a fiscal year's net income (after preferred stock dividends but before common stock dividends) divided by total equity (excluding preferred shares), expressed as a percentage. As with many financial ratios, ROE is best used to compare companies in the same industry.

High ROE yields no immediate benefit. Since stock prices are most strongly determined by earnings per share (EPS), you will be paying twice as much (in Price/Book terms) for a 20% ROE company as for a 10% ROE company.

The benefit comes from the earnings reinvested in the company at a high ROE rate, which in turn gives the company a high growth rate. The benefit can also come as a dividend on common shares or as a combination of dividends and reinvestment in the company. ROE is presumably irrelevant if the earnings are not reinvested.

• The sustainable growth model shows us that when firms pay dividends, earnings growth lowers. If the dividend payout is 20%, the growth expected will be only 80% of the ROE rate.
• The growth rate will be lower if the earnings are used to buy back shares. If the shares are bought at a multiple of book value (say 3 times book), the incremental earnings returns will be only 'that fraction' of ROE (ROE/3).
• New investments may not be as profitable as the existing business. Ask "what is the company doing with its earnings?"
• Remember that ROE is calculated from the company's perspective, on the company as a whole. Since much financial manipulation is accomplished with new share issues and buyback, always recalculate on a 'per share' basis, i.e., earnings per share/book value per share.