What Is the Price-to-Book (P/B) Ratio? Formula and Example

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The price-to-book (P/B) ratio compares a company’s stock market value with its book value, the accounting net worth left after subtracting total liabilities from total assets. You can calculate it per share (share price divided by book value per share) or for the whole company (market capitalization divided by total shareholders’ equity). Both give the same result. A P/B of 2.0 means investors are paying $2 for every $1 of net assets recorded on the balance sheet.

Value investors use the ratio to look for stocks that may be priced cheaply relative to their assets. Analysts also use it to check whether a high valuation is supported by the returns a company earns on its equity.

How the P/B ratio works

P/B ratio = Market price per share ÷ Book value per share

The equivalent company-level version is:

P/B ratio = Market capitalization ÷ Total shareholders’ equity

Book value per share

Book value per share (BVPS) is shareholders’ equity divided by the number of common shares outstanding:

BVPS = (Total assets − Total liabilities) ÷ Shares outstanding

If the company has preferred stock, analysts usually subtract the preferred equity before dividing. That leaves only the equity attributable to common shareholders, the people whose shares the market price refers to. Some calculations also subtract intangible assets, but that produces tangible book value, a different measure covered below.

Where the inputs come from

The share price is a market quote. It changes every trading day, so the P/B ratio moves with it. Total assets, total liabilities and shares outstanding come from the company’s balance sheet in its most recent quarterly or annual report. Because the balance sheet is updated only when the company reports, the standard P/B is a trailing measure: it pairs today’s price with book value from the last reported period.

Example of the P/B ratio

Hypothetical example for illustration only.

Company A reports the following on its latest balance sheet:

• Total assets: $100 million, with no intangible assets
• Total liabilities: $75 million
• Common shares outstanding: 10 million
• Current share price: $5.00

Step 1: book value. $100 million − $75 million = $25 million.

Step 2: book value per share. $25 million ÷ 10 million shares = $2.50.

Step 3: P/B ratio. $5.00 ÷ $2.50 = 2.0.

The company-level check gives the same answer. Market capitalization is $5.00 × 10 million = $50 million, and $50 million ÷ $25 million = 2.0.

A P/B of 2.0 says the market values Company A at twice its accounting net worth. Whether that is expensive depends on peers: if similar companies in the same sector trade at 1.2, Company A looks expensive; if they trade at 3.5, it looks cheap. It also depends on whether Company A earns enough on that $25 million of equity to justify the premium.

Now suppose Company A instead held $10 million of its $100 million in assets as goodwill from an acquisition. Total book value would still be $25 million, so P/B stays at 2.0. Tangible book value, however, would be $15 million, or $1.50 per share. That gives a price-to-tangible-book ratio of $5.00 ÷ $1.50 ≈ 3.33. The same stock looks much richer once you strip out assets that cannot easily be sold.

Interpreting the P/B ratio

P/B below 1.0

When P/B is under 1.0, the stock trades for less than the company’s net assets on paper. In theory, if the company sold everything at book value and paid off its debts, shareholders would receive more than the current share price.

There are other explanations, though. The market may doubt that the assets are really worth their book value, for example inventory that is obsolete or loans that may not be repaid. The company may be losing money, which erodes equity over time. Companies in financial distress sometimes trade below book for exactly these reasons, so a sub-1.0 ratio is a reason to investigate, not a conclusion.

P/B above 1.0

Market value of equity is typically higher than book value, which puts most P/B ratios above 1.0. Part of the reason is accounting conservatism. Many valuable things a company creates never appear on its balance sheet at full value.

Research and development is the standard illustration. Companies generally expense R&D costs as incurred, which lowers earnings and therefore book value, yet that spending can produce patents, proprietary processes or products that generate revenue for years. Investors may price that value into the stock even though the balance sheet shows none of it. The same applies to brands, customer relationships and software built in-house, so a high P/B can reflect real economic value rather than speculation.

Compare within an industry

P/B levels vary a great deal by industry because balance sheets look so different from one industry to the next. A manufacturer with factories and equipment carries a large book value. A software company may carry very little. Comparing their P/B ratios directly would be misleading. The useful comparisons are against similarly structured companies in the same sector, against the company’s own history, and against the broader market at the time.

P/B and return on equity

A P/B ratio becomes much more informative when you pair it with return on equity (ROE), which measures net income as a percentage of shareholders’ equity. The two are linked mathematically. With earnings and book value measured over consistent periods:

P/B = P/E × ROE

A company that earns a high return on its equity should, all else equal, command a higher multiple of that equity. Investors pay more for a dollar of book value that produces 20 cents of annual profit than for one that produces 5 cents.

Hypothetical example: two companies each trade at a P/E of 15. Company X has an ROE of 20%, so its P/B is 15 × 0.20 = 3.0. Company Y has an ROE of 6%, so its P/B is 15 × 0.06 = 0.9. Company Y’s lower P/B is not a bargain signal by itself. It simply reflects weaker returns on its equity.

The warning sign is a mismatch. A stock with a high P/B but a low ROE is priced as if its equity were highly productive when the reported results say otherwise, a combination that often shows up in overvalued growth stocks. When ROE and P/B move roughly together, the valuation is at least consistent with the company’s profitability.

What is a good P/B ratio?

No single number marks a stock as cheap or expensive. Value investors have traditionally treated a P/B under 1.0 as attractive, since it means paying less than accounting net worth. Others screen with a looser benchmark, such as a P/B under 3.0.

Benjamin Graham, the founder of value investing, set a combined test in The Intelligent Investor. He suggested a defensive investor avoid stocks trading above 1.5 times book value, while allowing a higher P/B if the P/E was low enough that P/E multiplied by P/B stayed at or below 22.5 (15 × 1.5).

In practice, a good P/B depends on the industry and on the overall level of valuations in the market. A stock screener can filter by P/B, but the output is a starting list, not a verdict.

P/B vs. price-to-tangible-book ratio

The price-to-tangible-book value ratio (P/TBV, sometimes PTBV) uses tangible book value in the denominator:

Tangible book value = Total book value − Intangible assets (including goodwill)

P/TBV = Share price ÷ Tangible book value per share

Intangible assets include patents, trademarks, intellectual property and goodwill, which is the premium a company records when it buys another business for more than the fair value of its identifiable net assets. These items can be hard to value and may be worth little if the company has to sell assets quickly. Removing them gives a stricter view of what backs each share, which is why P/TBV is widely used for banks and other companies where hard assets matter most. Because tangible book value can never exceed total book value, a company’s P/TBV is always equal to or higher than its P/B whenever both are positive.

P/B vs. other valuation ratios

P/B, P/E and price-to-sales (P/S) all divide the market price by a fundamental figure, but each uses a different one:

• P/B uses shareholders’ equity, a balance-sheet stock of value at one point in time.
• P/E uses earnings, a flow over a period. It relies on earnings per share.
• P/S uses revenue, which stays positive even when a company is unprofitable.

P/B has one practical advantage over P/E: it still works for companies with positive book value but negative earnings, when a P/E ratio is meaningless. Far fewer companies have negative book value than negative earnings. Book value also tends to be more stable from quarter to quarter than earnings, which makes it an intuitive anchor to compare against the price.

Limitations of the P/B ratio

The ratio is only as reliable as the book value behind it, and several common situations weaken it:

• Asset-light businesses. Service, software and information technology companies often have few tangible assets. Their book value understates their earning power, so their P/B ratios look high and say little about value.
• Different accounting standards. Companies reporting under different rules, especially across countries, may record assets and liabilities differently, so their P/B ratios may not be comparable.
• Negative book value. A long series of losses can push equity below zero, at which point the ratio cannot be used for relative valuation. Large share buybacks can produce the same result even at a profitable company, because repurchases reduce equity.
• One-off distortions. Recent acquisitions add goodwill, write-offs shrink assets, and buybacks reduce equity. Each can shift book value sharply without any change in the underlying business.
• Historical cost. Many assets are carried at purchase price minus depreciation. Land bought decades ago may be worth far more than its book value, while specialized equipment may be worth far less.
• Backward-looking. P/B combines a current price with past balance-sheet data. It does not forecast cash flows, so a low ratio does not predict that the price will rise.

FAQs

The Bottom Line

Value investors and analysts can use P/B to spot stocks priced cheaply against their assets and to test whether a premium valuation matches returns on equity. The ratio works best compared with peers in the same industry and checked against ROE. Asset-light companies, goodwill, buybacks and historical cost accounting can distort book value, so a low P/B is a reason to investigate further.