Book value per share is shareholder equity divided by the number of shares. It's the accounting value of each share based on the balance sheet.
How it relates
Book value per share represents the net asset value attributable to each common share—essentially what shareholders would theoretically receive per share if the company liquidated all assets and paid all debts. Calculated from the balance sheet, this metric provides a floor valuation based on accounting values rather than market expectations.
The calculation:
Book Value Per Share = (Total Assets - Total Liabilities - Preferred Equity) / Common Shares Outstanding
Or equivalently:
Book Value Per Share = Common Shareholders' Equity / Common Shares Outstanding
For example, if common equity is $50 billion and 5 billion shares are outstanding, book value per share is $10.
Why book value per share matters:
- Valuation anchor: Price-to-book ratio compares market price to book value
- Asset-heavy industries: Banks, insurers, and REITs often trade near book value
- Value investing: Stocks trading below book value may be undervalued (or impaired)
- Tangible floor: Represents accounting-based minimum value
Interpreting price-to-book:
- P/B < 1.0: Trading below book value; either undervalued or market expects write-downs
- P/B 1.0-2.0: Common for asset-intensive businesses
- P/B > 3.0: Market values intangibles, growth, or earning power above assets
- P/B > 10.0: Typical for asset-light tech companies where book value is less relevant
Important limitations:
- Historical cost: Assets recorded at purchase price, not current market value
- Intangibles excluded: Brands, patents, human capital not fully reflected
- Goodwill risk: Acquired goodwill may be overstated and subject to write-downs
- Industry variation: Less meaningful for service or tech companies with few tangible assets
Track book value per share growth over time. Consistent increases indicate the company is building equity value. Declining book value per share, especially from write-downs or accumulated losses, signals deteriorating financial position.