Book value is the net asset figure on a company’s balance sheet. It is the amount left for shareholders if you subtract total liabilities from total assets.
Investors often divide it by the number of shares to get book value per share, then compare the result with the share price through the price to book ratio.
What exactly sits inside book value?
On the balance sheet, book value usually appears as shareholders’ equity. It adds up items such as paid-in share capital, share premium, retained earnings, reserves and accumulated other comprehensive income. Treasury shares, if any, are deducted. The basic equation is simple: assets minus liabilities equals equity. The detail behind those lines is where it gets nuanced.
Assets are generally carried at historical cost less depreciation or amortisation, with some items remeasured at fair value. Liabilities include borrowings, lease obligations, trade payables and provisions. Depending on accounting rules, pension deficits, deferred tax balances and revaluation reserves can move equity without passing through the income statement.
Accounting standards differ by jurisdiction and can change, so two companies in different markets might measure similar items in different ways. That is one reason investors look inside the equity footnotes rather than relying on a headline total.
Book value per share: how to calculate it
The plain formula is:
Book value per share = shareholders’ equity ÷ number of shares outstanding.
Some analysts prefer to use diluted shares if there are options, convertibles or other potential share issuances. That gives a more conservative per share figure.
Three quick checks help avoid errors:
- Use the equity attributable to ordinary shareholders, not total equity if there are non-controlling interests or preference shares.
- Match the share count to the same reporting date as the balance sheet.
- Be consistent about basic versus diluted shares when comparing companies.
Tangible book value: why goodwill is often stripped out
Many investors calculate tangible book value by removing goodwill and other intangible assets from equity. The idea is to focus on net assets you could, in theory, sell or realise in a wind-down. For acquisitive companies, large goodwill balances arise when they pay more than the fair value of the acquired net assets. That goodwill can sit on the balance sheet for years unless it is impaired.
Tangible book value = shareholders’ equity − goodwill − other intangibles.
This adjustment matters most for banks, insurers and capital-intensive businesses where reported assets are closer to economic value. It is less informative for software or brand-led firms where much of the business value sits in people, code and customer relationships that are not fully recognised as assets. If a company has grown by acquisition, checking both book and tangible book can help you see how much of equity is tied up in purchased intangibles.
Where investors use book value in practice
Book value shows up in several common checks:
- Price to book (P/B). Share price divided by book value per share. A ratio below one suggests the market values the company at less than its net assets, which can indicate distress, poor returns or conservative accounting. A high P/B can reflect strong expected profitability or a business light on tangible assets.
- Return on equity (ROE). Net income divided by average equity. Book value is the base that earnings are compared to. Rising ROE with a stable P/B can signal improving quality.
- Capital adequacy for financials. For banks and insurers, equity and tangible equity are watched as loss-absorbing buffers, though regulatory capital frameworks have their own definitions.
Value-focused investors sometimes look for companies trading near or below tangible book, especially in cyclical sectors or during downturns. Growth investors pay less attention unless equity is a constraint on expansion.
What moves book value up or down over time
Book value is not static. Several recurring items change it:
- Profits and losses. Retained earnings increase equity, while losses reduce it. Dividends decrease equity because cash leaves the company.
- Share issuances and buybacks. Issuing new shares for cash generally increases equity. Buybacks reduce equity and reduce the share count. The effect on book value per share depends on the buyback price. Buying back below current book value per share tends to lift it. Buying back above tends to dilute it.
- Asset write-downs and impairments. Recognising that an asset is worth less than its carrying value cuts equity. The same is true for credit losses on receivables or loans.
- Foreign exchange translation. For multinationals, currency moves can flow through reserves and shift equity without affecting profit that year.
- Pension remeasurements and fair value reserves. These can move equity through other comprehensive income depending on the standard applied.
Because these items can be lumpy, comparing average book value over several periods often paints a clearer picture than a single snapshot.
Book value, market value and other lookalike terms
Several related terms are easy to mix up:
- Market value is what investors are paying for the equity today, usually shown as market capitalisation. It is the share price multiplied by shares outstanding. Market value and book value often differ, sometimes by a lot.
- Net asset value (NAV) is the fund-world version of book value, commonly used by investment trusts and funds. It reflects the fair value of portfolio holdings less liabilities, then per share.
- Par value or face value is a nominal amount printed on a share certificate or a bond. It has little to do with a company’s equity book value.
- Liquidation value estimates what assets might fetch in a forced sale after costs. Book value is not a guarantee of that outcome.
- Carrying value of a bond may be called book value in fixed income. That is the accounting value of the bond on a holder’s balance sheet, which can differ from market price.
A short worked example
Imagine a manufacturer reports total assets of £500 million and total liabilities of £350 million. Shareholders’ equity is therefore £150 million. If there are 50 million shares outstanding, book value per share is £3.00.
Say goodwill and other intangibles add up to £40 million. Tangible book value becomes £110 million, or £2.20 per share.
If the market values the company at £250 million, the P/B ratio is £250 million divided by £150 million, which is about 1.67. The price to tangible book is £250 million divided by £110 million, which is around 2.27.
Now consider a buyback. If the company repurchases £10 million of shares at a price below £3.00 per share, the share count falls and equity falls by £10 million, but book value per share is likely to rise. If it buys back at a much higher price, book value per share will likely fall. The direction depends on the relationship between buyback price and current book value per share.
How much weight should you give book value?
Book value is most informative where assets and liabilities are measured close to economic reality and where returns on those assets drive earnings. That tends to be the case for banks, insurers, commodity producers and some industrials. It is least informative for software, marketplaces and other asset-light businesses where the main assets do not sit fully on the balance sheet.
The best use is as one lens among many. Pair it with profitability measures, cash generation and the stability of the accounting. Always read the notes. Rules vary by country and can change, and companies have choices in how they measure items. Understanding those choices is often the difference between a cheap stock and a value trap.