Price-to-Sales and Price-to-Book: When Each Valuation Ratio Is Useful

Alpha Sentinel is a software platform, not a registered investment adviser. This article is educational, not investment advice. Full disclaimer at the end of this post.

It is a Sunday evening, you are reading about a company you have followed for a while, and the usual valuation ratio will not work: the company reports a loss, so there is no meaningful price-to-earnings figure to look at. This is where price-to-sales and price-to-book come in. Price-to-sales compares a company's market value with its revenue, and price-to-book compares it with the accounting value of its net assets. Each answers a question that earnings-based ratios cannot always answer, and each has blind spots that matter as much as the number itself.

Key Takeaways

• Price-to-sales divides market value by revenue and is often used when a company has little or no profit.
• Price-to-book divides market value by book value of equity and fits asset-heavy businesses such as banks and insurers best.
• Neither ratio is meaningful alone: compare it with similar companies and with the same company's own history.
• Price-to-sales ignores profit margins and debt, while price-to-book can be distorted by buybacks, intangible assets and accounting choices.
• A low ratio is not a bargain by definition, and a high ratio is not a warning by definition.

Why Does the Familiar Earnings Ratio Sometimes Fall Short?

The price-to-earnings ratio is the most quoted valuation measure because it ties price to profit. It works well for a stable company that earns a profit, but it breaks down in several common situations. A company with a net loss has no meaningful ratio. A company that earned a very small profit this year produces a huge, unhelpful ratio. A cyclical business, such as a producer of commodities or an industrial manufacturer, can show very high earnings at the top of a cycle and very low earnings at the bottom, which makes its ratio swing in ways that reflect timing more than value.

Earnings can also be shaped by one-time items, accounting choices and tax effects. So analysts often look at other denominators that are harder to move or that capture a different aspect of the business. Revenue is one, because it sits at the top of the income statement and is rarely negative. Book value is another, because it comes from the balance sheet and describes what the company owns and owes. No single ratio gives a complete answer, which is why professionals typically use several together and compare each against peers.

What Gaps Do These Alternatives Leave, and What Do People Get Wrong?

The common mistake is to treat a low ratio as proof of a bargain. A low price-to-sales may simply reflect thin margins, so each dollar of revenue produces little profit. A low price-to-book may reflect assets that are worth less than their recorded value, or a business that earns poor returns on its equity. In both cases the market could be pricing in real problems rather than overlooking value.

The opposite mistake is to dismiss a high ratio as expensive without asking what supports it. A fast-growing company may justify a high price-to-sales if its margins are likely to rise as it scales, though that is a forecast rather than a fact. Comparing ratios across industries is another trap: a software company and a grocery chain have very different margin structures, so their price-to-sales ratios are not comparable. Before using either ratio, the reader should know what it leaves out.

When Is Price-to-Sales Useful?

Price-to-sales is calculated as market capitalization divided by total revenue over the past twelve months, or equivalently the share price divided by revenue per share. It is most often used for companies that are growing but not yet earning a profit, for businesses with temporarily depressed earnings, and for comparing companies within the same industry that have similar margin profiles.

Its strength is that revenue is harder to distort than profit. Its weakness is that it says nothing about how much of each sales dollar is kept. Two companies with the same price-to-sales can have very different profit margins, and heavy debt is invisible to it, since revenue is the same whether the business is financed with equity or borrowed money. Analysts sometimes substitute enterprise value, which adds debt and subtracts cash, in the numerator to correct for this. A sensible approach is to read price-to-sales next to gross margin, operating margin and growth rate, and to compare it only with close peers.

When Is Price-to-Book Useful?

Price-to-book divides market capitalization by book value, which is total assets minus total liabilities, also called shareholders' equity. A ratio of 1 means the market values the company at exactly its accounting net worth. It is most informative for businesses whose value is tied to their balance sheets, such as banks, insurers, real estate companies and other asset-heavy firms.

It is far less useful for companies whose value comes from things that do not appear on the balance sheet. A software or consulting firm builds its worth in brands, code and people, and accounting rules generally do not capitalize most of that. Share buybacks, losses and write-downs also reduce book value, so a company can show a high price-to-book ratio simply because it has returned a lot of capital to shareholders. Some investors use tangible book value, which removes goodwill and other intangibles, to take a more conservative view. As with sales, the ratio gains meaning when read alongside return on equity and compared with similar companies.

How Would You Put Both to Work in a Real Week? (An Illustration)

The following is an illustration with invented, general details, not a record of results or a suggestion about any company. Imagine a physician who wants to understand why two companies he follows look so different on a valuation screen. One is an unprofitable, fast-growing business, and the other is a regional bank.

On Sunday he writes down the question he is trying to answer for each: what is the market paying for here? For the growing company he calculates price-to-sales and writes next to it the gross margin and revenue growth from the latest annual report. For the bank he calculates price-to-book and records return on equity. On Wednesday he finds the same ratios for a few similar companies and sees whether his two stand above or below their peers. On Saturday he lists what each ratio could not tell him, such as debt for the first company and loan quality for the bank. He ends with a list of questions to research, not a conclusion. Any decision about whether to own either company stays his, and for tax or planning questions he would consult a qualified professional.

Frequently Asked Questions

What is a good price-to-sales ratio?

There is no universal answer, because the range depends heavily on the industry and the company's margins. A ratio that is typical for a software company would be unusually high for a grocery chain. Compare with close peers and the company's own history, and read it next to profit margins and growth.

Is a price-to-book ratio below 1 a sign of an undervalued stock?

Not necessarily. It means the market values the company at less than its accounting net worth, which can reflect an undervalued business but also assets that are overstated or a business earning poor returns. Check asset quality and earnings quality before drawing a conclusion.

Which ratio is better for banks?

Price-to-book, often alongside return on equity, is the standard starting point for banks, because their value is tied closely to the balance sheet. Price-to-sales is less informative for them, since revenue includes interest flows that depend on the structure of lending and funding.

Where do I find the numbers to calculate these ratios?

Revenue and shareholders' equity appear in a company's annual report on Form 10-K and quarterly report on Form 10-Q, which are available on the SEC's EDGAR database. Divide market capitalization by revenue for price-to-sales, and by shareholders' equity for price-to-book.

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