What is Book Value Per Common Share

Book value per common share is a formula used to calculate the per share value of a company based on common shareholders' equity in the company.  Should the company dissolve, the book value per common share indicates the dollar value remaining for common shareholders after all assets are liquidated and all debtors are paid.

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Understanding Book Value

BREAKING DOWN Book Value Per Common Share

The book value per common share (formula below) is an accounting measure based on historical transactions:

Formula to calculate Book Value Per Common Share

The book value of common equity in the numerator reflects the original proceeds a company receives from issuing common equity, increased by earnings or decreased by losses, and decreased by paid dividends. A company's stock buybacks decrease the book value and total common share count. Stock repurchases occur at current stock prices, which can result in a significant reduction in a company's book value per common share. The common share count used in the denominator is typically an average number of diluted common shares for the last year, which takes into account any additional shares beyond the basic share count that can originate from stock options, warrants, preferred shares, and other convertible instruments.

The Difference Between Market Value per Share and Book Value per Share

The market value per share is a company's current stock price, and it reflects a value that market participants are willing to pay for its common share. The book value per share is calculated using historical costs, but the market value per share is a forward-looking metric that takes into account a company's earning power in the future. With increases in a company's estimated profitability, expected growth, and safety of its business, the market value per share grows higher. Significant differences between the book value per share and the market value per share arise due to the ways in which accounting principles classify certain transactions.

For example, consider a company's brand value, which is built through a series of marketing campaigns. U.S. generally accepted accounting principles (GAAP) require marketing costs to be expensed immediately, reducing the book value per share. However, if advertising efforts enhance the image of a company's products, the company can charge premium prices and create brand value. Market demand may increase the stock price, which results in a large divergence between the market and book values per share.