Price-to-Book Ratio Calculator
Calculate the price-to-book (P/B) ratio comparing a stock's market price against its book value per share. Used by value investors to identify potentially undervalued stocks trading below their accounting net asset value.
Last updated: May 2026
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About this calculator
The formula is: P/B = marketPrice / bookValuePerShare. Book value per share = (total assets − total liabilities) / shares outstanding, also called shareholders' equity per share — the accounting net worth of the company divided by its share count. P/B = 1.0 means the market values the company exactly at its accounting net assets; P/B = 2.0 means the market values it at twice book; P/B = 0.5 means the market values it at half book (deeply distressed or "value trap" territory). Edge cases: zero or negative book value (companies with cumulative losses exceeding contributed capital) makes the formula meaningless or produces negative ratios; very small book values produce extreme P/B for asset-light businesses. Historical use: Benjamin Graham's "net-net" stocks (P/B < 1.0, ideally with positive earnings) formed a quantitative value framework that worked exceptionally well in the 1930s–1970s era of asset-heavy industrial businesses. Modern application is more nuanced because of accounting changes: 1) Asset-light businesses (software, services, consumer brands) have minimal book value relative to economic value — Apple's tangible book is a fraction of market cap; Coca-Cola's brand value is essentially unbooked. 2) Recent accounting standards (ASC 805 goodwill, fair value adjustments) distort book value with mark-to-market and impairment cycles. 3) Buybacks reduce book value (buybacks at premium to book reduce equity) while often being good for shareholders; pure book value math penalizes these companies. 4) Goodwill on the balance sheet from past acquisitions inflates book value but often gets written down. P/B remains most useful for: financial sector (banks, insurance) where book value approximates net asset value; capital-intensive industries (REITs, utilities, industrials) where physical assets matter; deep value screens looking for distressed turnaround candidates. For tech, consumer brands, and services, P/B is largely irrelevant and should be ignored.
How to use
Example 1 — Regional bank. PNC Financial: market price $185, book value per share $135 (Q4 2024). Enter market_price 185, book_value 135. Result: 185 / 135 = 1.37. ✓ P/B of 1.37 is typical for a healthy regional bank in 2025; the bank trades modestly above accounting book value reflecting franchise value and earnings power. Compare to historical range: regional banks typically traded 1.5–2.0 P/B in healthy environments, dropped below 1.0 during the 2008 financial crisis and again briefly during the 2023 regional bank stress. P/B < 1.0 on a solvent bank is often a buying opportunity for value investors. Example 2 — Software company. ServiceNow (NOW): market price $1,000, book value per share $30. Enter 1000, 30. Result: 1000 / 30 = 33.3. ✓ P/B of 33 is extreme — but expected for high-growth software with minimal physical assets and significant intangible value (customer relationships, recurring revenue moat, software code). The book value doesn't capture economic value for software businesses; market values them based on revenue growth, recurring revenue retention, and profit margins. P/B is essentially useless for analyzing NOW, MSFT, ADBE, and similar businesses; use price-to-sales, EV/revenue, EV/EBITDA, or rule-of-40 metrics instead.
Frequently asked questions
What is a "good" P/B ratio?
There is no universal threshold — varies dramatically by industry, business model, and economic cycle. Industry context matters enormously. Banks/financials: P/B 0.5–2.0 is the typical range; below 1.0 often signals distress or deep value; above 2.0 typically reflects very high ROE (Goldman Sachs, JPMorgan in strong years). Insurance: similar to banks, 0.8–1.8 typical. Utilities: 1.2–2.5; the regulated nature constrains both upside and downside. REITs: 1.0–2.0; sometimes priced at premium to net asset value, sometimes discount. Industrials: 1.5–4.0 for typical manufacturers; capital intensity drives the ratio. Tech/software: 5–50+; book value is essentially noise. Consumer brands: 5–20+; intangible brand value dominates. Healthcare/pharma: 3–10 typical; intellectual property and pipeline matter. Across all sectors, very low P/B (well below industry average) deserves investigation: is the company genuinely undervalued or facing fundamental problems (declining earnings, regulatory issues, technology disruption)? Very high P/B requires high ROE to justify; sustainable ROE × P/B should approximate cost of equity for valuation logic to work.
Why is book value declining as an investment metric?
Several reasons make book value less meaningful for modern stocks than it was historically. 1) Intangible asset shift: economy has moved from physical capital (factories, equipment) to intangibles (software, brands, network effects, data). Accounting captures physical assets at cost; most intangibles are not booked except through goodwill from acquisitions. Microsoft's software code, brand, and ecosystem are worth hundreds of billions but barely register on the balance sheet. 2) Buyback distortion: companies buying back stock above book value reduce shareholders' equity, making P/B appear higher; the buybacks are often value-enhancing despite this. 3) Goodwill effects: M&A activity creates goodwill on balance sheets at acquisition prices, which then gets impaired in down cycles; P/B swings wildly across acquisition and write-down cycles. 4) Tax distortions: deferred tax assets and liabilities can be huge book value items that are economically less meaningful than face value. 5) ESG and operating lease accounting changes (ASC 842, IFRS 16) have moved leases onto balance sheets, changing book value comparability before/after 2019. For tangible-asset-heavy financials and industrials, book value remains useful. For everything else, P/B is largely deprecated in favor of cash flow-based valuations (DCF, EV/EBITDA, free cash flow yield).
What is tangible book value and when should I use it?
Tangible book value = total stockholders' equity − goodwill − other intangibles. The metric removes accounting intangibles (goodwill from acquisitions, capitalized software, customer lists, patents) to get pure physical/financial assets. P/Tangible Book Value (P/TBV) is the corresponding ratio. P/TBV is more conservative than P/B because intangibles, particularly goodwill, can be impaired and disappear. For banks: P/TBV is the standard metric (not P/B) — bank balance sheets are highly fungible financial assets where tangible book closely tracks economic value. Bank P/TBV typically ranges 0.7–1.8; below 0.7 = distressed; above 1.8 = premium franchise. For acquirers with significant goodwill (consumer goods, healthcare conglomerates), P/TBV reveals how dependent the apparent book value is on past acquisition prices. For asset-heavy industrials, both P/B and P/TBV give similar signals because goodwill is a small portion. For asset-light businesses (services, technology), P/TBV is often near-zero or negative because most "value" is in intangibles or future cash flows, not booked physical assets. Use P/TBV: when analyzing banks, insurers, or companies with substantial goodwill from acquisitions. Use P/B: when intangibles are minimal and goodwill is small.
What are the most common P/B mistakes?
The biggest is applying P/B uniformly across industries without recognizing that book value means very different things in different businesses; tech P/B and bank P/B are not comparable. The second is interpreting P/B < 1.0 as automatically attractive; sometimes a company trades below book because the assets are impaired and book value is overstated (commercial real estate during downturns, energy companies during oil price collapses). The third is ignoring book value quality — heavily depreciated old equipment may have $10 book value but be functionally worthless; recent acquired goodwill may carry billions in book that gets written off. The fourth is using stale book value without considering quarterly changes; major asset write-downs, share buybacks, and dividends all change book value materially between reporting periods. The fifth is comparing across countries with different accounting standards (IFRS vs US GAAP vs Chinese GAAP) without normalizing; international comparisons require care. The sixth is failing to consider ROE alongside P/B; ROE × P/B = earnings yield, so high P/B is only justified by correspondingly high ROE. The seventh is using P/B for spin-offs or recent IPOs where book value reflects accounting adjustments not yet stabilized. The eighth is treating P/B as the only valuation metric for value investing; modern value frameworks combine P/B with quality (high ROE, low debt), profitability (positive earnings), and growth (Joel Greenblatt magic formula, Robert Novy-Marx quality). Single-factor P/B value strategies have underperformed multi-factor approaches consistently since the 1990s.
When should I not use P/B?
Skip it for software, services, consumer brands, and other intangible-asset-heavy businesses where book value is a tiny fraction of economic value; use price-to-sales, EV/EBITDA, or free cash flow yield instead. It is the wrong tool for companies with negative book value (cumulative losses exceeding contributed capital — common for early-stage biotechs, recent IPOs with large buybacks, or companies emerging from bankruptcy) where the ratio is mathematically meaningless. Do not use it for REITs that report on FFO/AFFO basis; price-to-NAV is more relevant for real estate. For commodity-cycle companies near peak earnings, P/B at peak may look reasonable just before earnings collapse; pair with normalized earnings analysis. For pre-revenue companies (biotechs, early SaaS), book value primarily reflects raised capital and burn rate, not economic value; use pipeline NPV or comp-based price-per-employee metrics. For private market valuations, the public market P/B does not transfer; private comparable transactions are more relevant. For deeply leveraged companies, equity book value is small relative to enterprise value; use EV-based metrics. And during severe market dislocations (2020 COVID, 2008 crisis), book values were temporarily distorted; wait for stabilization before relying on the ratio.