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The Price to Book (P/B) Ratio

Investing in the stock market requires a keen eye for value, and one of the essential tools in an investor’s toolkit is the Price to Book ratio (P/B ratio).

At its core, the P/B ratio is a tool to compare a company’s market value to its book value. Let’s break that down a little. The market value is simply the current stock price multiplied by the total number of outstanding shares, reflecting how much investors are willing to pay for a share of the company. On the other hand, the book value is derived from a company’s financial statements and represents the net asset value of the company according to its balance sheet, calculated as total assets minus liabilities.


P/B Ratio=Market Price per ShareBook Value per Share\text{P/B Ratio} = \frac{\text{Market Price per Share}}{\text{Book Value per Share}}

To find the book value per share, you would divide the total book value by the number of outstanding shares:

Book Value per Share=Total AssetsTotal LiabilitiesTotal Shares Outstanding\text{Book Value per Share} = \frac{\text{Total Assets} - \text{Total Liabilities}}{\text{Total Shares Outstanding}}

Example Calculation

Consider a company with:

  • Total assets of $1,000,000
  • Total liabilities of $600,000
  • 100,000 shares outstanding
  • A current stock price of $8

First, we calculate the book value per share:

Book Value per Share=$1,000,000$600,000100,000=$400,000100,000=$4\text{Book Value per Share} = \frac{\$1,000,000 - \$600,000}{100,000} = \frac{\$400,000}{100,000} = \$4

Then, apply the formula for the P/B ratio:

P/B Ratio=$8$4=2\text{P/B Ratio} = \frac{\$8}{\$4} = 2

This P/B ratio of 2 indicates that the market values the company at twice its book value.

Using the P/B Ratio

Investors use the P/B ratio to identify potential investment opportunities. A lower P/B ratio might suggest that a stock is undervalued compared to its actual net asset value, making it an attractive option for value investors. Conversely, a higher P/B ratio could suggest that the stock is overvalued or that investors expect substantial growth and are willing to pay a premium.

However, relying solely on the P/B ratio can be misleading. This metric is particularly useful for evaluating companies with significant tangible assets, like those in manufacturing or real estate. In contrast, it might not be as insightful for tech or service companies, where intangible assets such as intellectual property or brand value play a crucial role.

It’s also essential to compare the P/B ratio within the right context. Comparing a manufacturing company’s P/B ratio to that of a tech giant might not make sense. Instead, comparisons should be made within the same industry.

Additionally, a very low P/B ratio might indicate underlying problems within the company, such as financial instability or declining asset values. Therefore, while a useful tool, the P/B ratio should be used in conjunction with other metrics like the Debt-to-Equity ratio, Price to Earnings (P/E) ratio, and a thorough analysis of the company’s fundamentals and market conditions.


Overall, the Price to Book ratio is a valuable metric for making informed investment decisions, offering insights into whether a stock is potentially over or undervalued compared to its book value. With calculated discernment, it can guide investors toward robust investment strategies and profitable opportunities.