1. What Is the Price-to-Book Ratio?
The Price-to-Book ratio (P/B) compares a company's market value to its book value — the net worth recorded on its balance sheet. It answers a simple question: how much are investors paying for every dollar of the company's accounting net assets?
Book value is what would theoretically be left for shareholders if a company sold all its assets and paid off all its liabilities. It equals total assets minus total liabilities, also called shareholders' equity.
A P/B of 1.0 means the market values the company at exactly its accounting net worth. A P/B of 3.0 means investors pay three times book value — usually because they expect returns well above the value of the company's physical assets.
2. The Formula and an Example
Book value per share is total shareholders' equity divided by shares outstanding. Suppose a bank has $50 billion in equity and 1 billion shares:
If the stock trades at $60, the P/B ratio is $60 ÷ $50 = 1.2x — a 20% premium over the bank's accounting net worth.
Tip: Many analysts prefer tangible book value, which strips out intangibles like goodwill. This gives a more conservative "hard asset" measure, especially useful after large acquisitions.
3. What Is a "Good" P/B Ratio?
Traditionally, value investors looked for stocks trading below a P/B of 1.0 — buying a company for less than its net assets. Benjamin Graham favored low P/B ratios as a margin of safety.
- •P/B below 1.0 can signal an undervalued stock — or a business whose assets are worth less than they appear.
- •P/B of 1.0–3.0 is common for established, profitable companies.
- •P/B above 5.0 is typical for technology and brand-driven companies whose value lies in intangibles.
A low P/B only matters when paired with profitability. Combine it with return on equity — high ROE justifies a higher P/B.
4. Where P/B Works Best
P/B is most useful for companies whose value is tied to tangible, marked-to-market assets:
Banks & Insurers
Their assets are largely financial (loans, securities), so book value closely reflects real economic value. P/B is a primary valuation tool here.
Asset-Heavy Industries
Real estate, shipping, and industrials own factories, property, and equipment — physical assets P/B captures well.
By contrast, P/B is nearly useless for software or consumer-brand companies, whose value lives in intellectual property, network effects, and reputation.
5. Limitations and Pitfalls
Book value ignores intangibles
A leading software firm may have a huge market value but tiny book value, producing a sky-high P/B that says little about whether it's overpriced.
Accounting values can be stale
Assets are often carried at historical cost, not market value. Real estate bought decades ago may be worth far more than its book figure.
Buybacks distort book value
Aggressive repurchases can shrink equity and even push book value negative, making P/B meaningless.
6. Using P/B on WIT
On any stock detail page you'll find book value and balance-sheet metrics. To put P/B to work:
- Search a stock on the markets dashboard and open its page.
- Compare P/B within the same sector — a bank's 1.2x means something very different from a tech firm's 12x.
- Pair it with ROE from our ROE & ROIC guide to judge whether a premium is deserved.
- Cross-check the balance sheet using our balance sheet guide.