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ValuationP/E

What is the Price-to-Earnings Ratio (P/E)?

The Price-to-Earnings Ratio (P/E) is market price divided by earnings per share and is the most widely used equity valuation multiple. It tells investors how much they are paying for each dollar of current or expected earnings. A trailing P/E uses the last 12 months of reported earnings; a forward P/E uses the next 12 months of analyst-estimated earnings.

Cite this page

ValueMarkers (2026). "Price-to-Earnings Ratio Definition and Formula." Retrieved from

Formula

P/E = Share Price / Earnings Per Share (EPS)

Why the P/E Ratio Matters

The P/E ratio is the starting point for almost every equity valuation conversation. It is intuitive -- paying 15x earnings for a stable utility feels different from paying 80x earnings for a high-growth software company. But the multiple only makes sense in context: relative to history, peers, and the risk-free rate.

When interest rates are low, investors accept lower earnings yields (higher P/E multiples) because the alternative -- bonds -- offers very little return. When rates rise sharply, as in 2022, high-P/E growth stocks re-rate downward because the discount rate applied to future earnings rises, compressing their present value. Understanding this relationship between rates and P/E is essential for value investors navigating different macro environments.

Calculate Earnings Yield

The earnings yield (1 / P/E) is the P/E ratio inverted -- it expresses earnings as a percentage of price, making it directly comparable to bond yields. Use our Earnings Yield Calculator to benchmark any stock against Treasuries.

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Frequently Asked Questions

What is the P/E ratio?+
The P/E ratio (price-to-earnings ratio) divides a stock price by its earnings per share. If a stock trades at $50 and earned $5 per share over the past year, its trailing P/E is 10. It tells you how many years of current earnings you are paying for the stock, assuming earnings stay flat. A P/E of 20 means you are paying 20 times current annual earnings.
What is a good P/E ratio?+
There is no universally "good" P/E because the appropriate multiple depends on earnings growth, interest rates, and business quality. Historically the S&P 500 has traded at an average trailing P/E of roughly 15-16x. A fast-growing company with durable competitive advantages may fairly command a P/E of 30x or higher. A cyclical or declining business at 10x may still be overvalued. Always compare P/E to the company's own history, its sector peers, and the broader market.
What is the difference between trailing and forward P/E?+
Trailing P/E (also called LTM or TTM P/E) uses actual reported earnings from the last 12 months. Forward P/E uses consensus analyst estimates for the next 12 months. Forward P/E is lower than trailing P/E when earnings are expected to grow, which makes growth stocks appear cheaper on a forward basis. During recessions, forward P/E can be misleading if analysts are too slow to cut estimates.
Is a low P/E always better?+
Not necessarily. A low P/E can indicate a bargain or a "value trap." Companies with structurally declining earnings, heavy debt, or regulatory risk often trade at low multiples for good reason. Benjamin Graham distinguished between a stock that is cheap because of temporary pessimism (opportunity) and one that is cheap because its business is genuinely deteriorating (trap). Always examine the quality and sustainability of earnings, not just the multiple.

Related Terms

Earnings Per Share

Net income divided by shares outstanding

Price-to-Book Ratio

Market price vs net asset value

Graham Number

Benjamin Graham's intrinsic value upper bound

Equity Risk Premium

Excess return equities must earn over Treasuries

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