What P/E means
Price-to-earnings = share price ÷ earnings per share. A P/E of 20 means you are paying $20 for each $1 of annual earnings per share.
The beginner shortcut for EPS is net income ÷ shares. The reported figure, basic EPS, is earnings available to common shareholders (net income minus preferred dividends) ÷ the weighted-average number of common shares outstanding during the period. Diluted EPS also counts shares that could be created from options, convertibles and similar instruments. EPS does not require any dividend to be paid.
It is a shorthand for how much optimism is already priced in, not a measure of quality.
Why a low P/E is not automatically cheap
A low multiple often reflects a business the market expects to shrink. A high multiple can be reasonable for a business growing durably. Comparing multiples across different industries is usually meaningless.
There is no universal "cheap" or "expensive" P/E number; any threshold in an example is an illustrative assumption. P/E is also distorted by cyclical earnings (low P/E at a profit peak), is meaningless when earnings are negative, can shift with dilution, and depends on accounting choices and one-off items.
Other common measures
Different business types demand different lenses.
- P/S (price to sales): used when a company is not yet profitable
- P/B (price to book): more relevant for banks and asset-heavy businesses
- EV/EBITDA: accounts for debt in the comparison
- Free cash flow yield: cash generated relative to the price paid
Valuation is a lens, not a prediction
On this platform, Valuation Intelligence is a research lens that describes how a company's current valuation compares to its own history, its peers and its cash generation. It is not a fair value estimate, not a price target and not a return forecast, and it contributes nothing to the Pro Investor Score™.
e.g. $50 (hypothetical)
e.g. $2.50 (hypothetical)
e.g. 20x (hypothetical)
P/E is a shorthand for the price paid per dollar of current earnings, always read in context.
Educational example
Costco Wholesale Corporation (COST)
Costco has often traded at a higher P/E than typical retailers, which is a prompt to ask why, not a verdict on its own. Comparing its multiple against its own history and against genuinely similar membership-model retailers, using figures from its filings, is the right way to use an example like this.
Explore the full company researchNamed to illustrate the concept only. This is not a recommendation to buy or sell any investment.
Key concepts
Select a term to read its definition.
P/E ratio
Share price divided by earnings per share — how much is paid per dollar of current earnings.
Full explanation of P/E ratioEPS
Earnings per share. Basic EPS is earnings available to common shareholders divided by weighted-average common shares; diluted EPS also counts potential shares from options and convertibles.
Full explanation of EPSEV/EBITDA
Enterprise value (roughly market capitalization plus debt minus cash) divided by earnings before interest, taxes, depreciation and amortization. EBITDA is not a standard accounting measure, so definitions vary.
View in the glossaryFree cash flow yield
Free cash flow divided by market capitalization. Because free cash flow is defined differently by different sources, check which definition is used.
View in the glossary
Why this matters
Valuation tells you what expectations you are inheriting when you buy.
Check your understanding
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Key takeaways
- P/E is share price divided by earnings per share
- A low or high multiple is a question about expectations, not an automatic verdict
- Different business types call for different valuation measures
- Valuation is a research lens, never a price target or forecast
Related concepts
- Written by
- Pro Investor Academy Research Team
- Content type
- Educational article
- Published
- 2026-09-13
- Last reviewed
- 2026-09-13
Sources
- EDGAR full-text and structured filing data — U.S. Securities and Exchange Commission
Regulatory document · U.S.
- Intelligent Accumulation methodology — Pro Investor Academy
Pro Investor Academy methodology
Educational content only. This lesson is not investment, tax or legal advice and does not recommend buying or selling any specific investment. All investing involves the risk of loss.
