What Is the Price-to-Book (P/B) Ratio?
The price-to-book ratio compares what the market says a company's equity is worth to what the balance sheet says it is worth. It is calculated as P/B = Equity Value / Book Value of Shareholders' Equity, or on a per-share basis as share price divided by book value per share.
Book value equals total assets minus total liabilities, so P/B effectively asks how much of a premium investors will pay over the accounting value of the company's net assets. A ratio above 1.0x means the market believes the business creates value beyond its recorded assets, while a ratio below 1.0x can signal distress, poor returns, or a potential bargain.
How It Works
P/B is most useful where balance sheet values closely track economic reality, which is why it dominates the valuation of banks and insurance companies whose assets and liabilities are largely financial instruments marked near fair value. For these businesses, P/B is often analyzed alongside return on equity, since a bank earning a higher ROE deserves a higher multiple of its book value.
For asset-light companies like software firms, P/B is far less informative because their most valuable assets, such as brands, code, and people, are largely absent from the balance sheet. Intangibles and goodwill from past acquisitions can also inflate book value, so analysts sometimes use tangible book value, which strips those items out.
Example
A regional bank has 50 million shares trading at $30, so its equity value is $1.5 billion. Its balance sheet shows shareholders' equity of $1.2 billion, giving a P/B of $1.5B / $1.2B = 1.25x, or equivalently $30 divided by book value per share of $24.
If peer banks with similar ROEs trade at 1.5x book, applying that multiple implies a value of 1.5 x $24 = $36 per share. In interviews for financial institutions groups, expect to be asked why banks are valued on P/E and P/B rather than EV/EBITDA, and the answer is that interest is a core operating item for banks, making enterprise value ill-defined.
Why It Matters
P/B anchors valuation in the financial sector, informs the classic value-investing screen for stocks trading below book, and pairs with ROE to link profitability to valuation. Regulators and acquirers of banks think in terms of multiples of tangible book value, so the metric has direct deal relevance.
Its key limitation is accounting dependence: historical-cost assets, impairments, and buybacks can push book value far from economic value, so P/B should always be interpreted with an eye on what actually sits inside shareholders' equity.
