Book Value : Formula & Calculation

What Is Book Value?

Book value is equal to the cost of carrying an asset on a company's balance sheet, and firms calculate it netting the asset against its accumulated depreciation. As a result, book value can also be thought of as the net asset value (NAV) of a company, calculated as its total assets minus intangible assets (patents, goodwill) and liabilities. For the initial outlay of an investment, book value may be net or gross of expenses such as trading costs, sales taxes, service charges, and so on.

The formula for calculating book value per share is the total common stockholders' equity less the preferred stock, divided by the number of common shares of the company. Book value may also be known as "net book value" and, in the U.K., "net asset value of a firm."

Understanding Book Value

Book value is the accounting value of the company's assets less all claims senior to common equity (such as the company's liabilities). The term book value derives from the accounting practice of recording asset value at the original historical cost in the books.

While the book value of an asset may stay the same over time by accounting measurements, the book value of a company collectively can grow from the accumulation of earnings generated through asset use. Since a company's book value represents the shareholding worth, comparing book value with the market value of the shares can serve as an effective valuation technique when trying to decide whether shares are fairly priced.

As the accounting value of a firm, book value has two main uses:

1. It serves as the total value of the company's assets that shareholders would theoretically receive if a company was liquidated.
2. When compared to the company's market value, book value can indicate whether a stock is under- or overpriced.

Book value per share (BVPS) is a method to calculate the per-share book 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. If a company’s BVPS is higher than its market value per share, then its stock may be considered to be undervalued.

In personal finance, the book value of an investment is the price paid for a security or debt investment. When a company sells stock, the selling price minus the book value is the capital gain or loss from the investment.

Mark to Market Valuation

There are limitations to how accurately book value can be a proxy to the shares' market worth when mark to market valuation is not applied to assets that may experience increases or decreases of their market values.

For example, real estate owned by a company may gain in market value at times, while its old machinery can lose value in the market because of technological advancements. In these instances, book value at the historical cost would distort an asset or a company's true value, given its fair market price.

Price-to-Book Ratio

Price-to-book (P/B) ratio as a valuation multiple is useful for value comparison between similar companies within the same industry when they follow a uniform accounting method for asset valuation. The ratio may not serve as a valid valuation basis when comparing companies from different sectors and industries whereby some companies may record their assets at historical costs and others mark their assets to market.

As a result, a high P/B ratio would not necessarily be a premium valuation, and conversely, a low P/B ratio would not automatically be a discount valuation.