Price-to-Book Ratio Calculator
Enter a share price and book value per share to get the P/B ratio instantly. Switch to company-level inputs and the calculator derives book value per share from total stockholder equity and shares outstanding. Toggle tangible book value mode to strip out intangible assets and goodwill for a more conservative view favored by bank analysts. Results update as you type.
What is the price-to-book ratio?
The price-to-book ratio (P/B ratio, or PB ratio) compares a company's market capitalisation to the accounting value of its net assets. A P/B of 2.0x means investors are paying two dollars for every one dollar of book value on the balance sheet. It is one of the oldest and most widely used valuation multiples in equity analysis, tracing back to Benjamin Graham's value-investing framework, and remains central to screening for undervalued stocks, especially in banking and financial services. Book value (also called net book value or shareholders equity) is simply total assets minus total liabilities: the residual value that would theoretically be left for common shareholders if the company liquidated at balance-sheet values. Dividing that total by shares outstanding gives book value per share, the denominator of the per-share P/B formula.
How to calculate the P/B ratio
There are two equivalent routes to the same number: 1. Per-share method: P/B = Share price / Book value per share. Book value per share = (Total stockholder equity - Preferred equity) / Shares outstanding. 2. Company-level method: P/B = Market capitalisation / Book value of equity. Market capitalisation = Share price times shares outstanding. Both approaches yield the identical ratio because the shares outstanding terms cancel. The per-share method is quicker when a financial data site already reports book value per share. The company-level method is useful when you are building the calculation from raw balance-sheet lines. For banks and asset-heavy firms, analysts also compute the price-to-tangible-book (P/TBV) ratio, which strips out goodwill and other intangible assets before dividing: Tangible book value = Book value - Total intangibles and goodwill. Tangible book value per share = Tangible book value / Shares outstanding. P/TBV = Share price / Tangible book value per share. A company carrying large amounts of goodwill from acquisitions may look cheaper on the standard P/B than on P/TBV.
How to interpret the result
A P/B below 1.0 means the market values the company at less than its stated net assets. This is sometimes a value signal, but it can also flag genuine trouble: declining earnings, write-down risk, or a deteriorating capital position. Value traps (stocks that look cheap but keep falling) are common at sub-1 P/B. Always ask why the ratio is below 1 before calling something undervalued. A P/B between 1 and 3 is typical for many established, profitable businesses and is broadly considered fair to modestly valued territory. A P/B above 3 reflects market expectations of above-average returns or growth. Software, platform, and consumer-brand companies regularly trade at 5 to 20 times book because most of their value lies in intellectual property, customer relationships, and competitive moats that accounting rules do not fully capture on the balance sheet. Sector context is critical. Do not compare a bank's P/B of 1.2x to a software company's P/B of 15x and conclude the bank is cheap. Compare within the sector and against the company's own history.
Limitations and when not to use P/B
The P/B ratio loses meaning for companies where intangible assets dominate value: software firms, pharmaceutical companies with large drug pipelines, platform businesses, and service companies whose main asset is human capital and brand. In these cases, book value is small and the accounting P/B ratio is very high, not because the stock is expensive relative to true value, but because the balance sheet simply cannot capture the real assets. P/B also ignores earnings quality, cash generation, and growth prospects. A company can have a low P/B and a terrible business, or a high P/B and a world-class one. The most useful application is pairing P/B with return on equity (ROE). If a company earns a high ROE consistently, a high P/B is justified: investors rationally pay a premium when a business can compound book value quickly. The Gordon Growth Model implies P/B = (ROE - growth) / (cost of equity - growth), which shows that P/B and ROE should move together. Stocks trading at high P/B with low ROE are the danger zone.
Typical P/B ratios by sector
| Sector | Typical P/B range | Why |
|---|---|---|
| Banks and financial services | 0.8 - 1.5x | Asset-heavy; tangibles dominate |
| Insurance | 1.0 - 2.0x | Regulated, asset-heavy model |
| Utilities | 1.5 - 2.5x | Stable cash flows, limited growth |
| Industrials and manufacturing | 2.0 - 4.0x | Mix of tangibles and brand value |
| Consumer staples | 3.0 - 6.0x | Brand intangibles compress book value |
| Healthcare and pharma | 3.0 - 8.0x | R&D pipeline, patents not on balance sheet |
| Technology hardware | 4.0 - 10.0x | IP-intensive; some tangible scale |
| Software and internet | 5.0 - 20.0x+ | Intangibles dominate; book value low |
Approximate median ranges based on Damodaran NYU and Siblis Research data. Ratios vary with market cycles - use for orientation, not as precise benchmarks.
Frequently asked questions
What is a good P/B ratio?
There is no universal answer. For banks and insurers, a P/B near or slightly above 1 is typical and considered fair. For consumer-brand companies, a P/B of 3 to 6 is common. For software and technology firms, ratios of 10x or more are normal. The right benchmark is always the sector median or the company's own historical range, not a fixed absolute number. A P/B below 1 can be a value signal or a warning sign depending on the underlying business quality.
What is the difference between P/B and price-to-tangible-book (P/TBV)?
The price-to-book ratio uses all equity on the balance sheet, including goodwill and intangible assets acquired through deals. The price-to-tangible-book ratio strips those intangibles out, leaving only the hard, physical-type assets: cash, receivables, property, equipment, and investments. P/TBV is a more conservative measure and is the standard valuation metric for banks, where intangibles are small and tangible equity is the key buffer against losses.
Can the P/B ratio be negative?
Yes, if a company has negative book value, meaning total liabilities exceed total assets. This happens when accumulated losses have eroded equity, often after years of heavy debt-financed investment or persistent losses. A negative P/B ratio is not meaningful as a valuation multiple and the calculation is usually omitted. Examples include some airlines, retailers, and leveraged buyout targets that have returned capital through buybacks financed by debt.
Is a low P/B ratio always a buying signal?
No. A low P/B can mean the market expects the company to destroy value, write down assets, or dilute shareholders. These are sometimes called value traps. Low P/B stocks require additional due diligence: check the trend in book value (is it shrinking?), the return on equity, the quality of assets, and the debt load. A low P/B combined with a rising ROE and improving earnings quality is a stronger buying signal than a low P/B alone.
Why do technology companies have such high P/B ratios?
Technology companies invest heavily in intangible assets: software, patents, brand, and talent. Under standard accounting rules (GAAP and IFRS), most of these are expensed immediately rather than capitalised, so they never appear on the balance sheet. This keeps book value artificially low relative to the true economic value of the business, mechanically inflating the P/B ratio. A software firm with a P/B of 20x is not necessarily overvalued; it may simply be a business whose real assets are just not visible on the balance sheet.