PE Ratio History: What Is a Good PE Ratio in 2026?

What Is the PE Ratio?

The Price-to-Earnings (PE) ratio compares a company's stock price to its earnings per share (EPS):

It tells you how many years of current earnings you are paying for. A PE of 20x means you are paying $20 for every $1 of annual earnings — or equivalently, you "get your money back" in 20 years at the current earnings run-rate, ignoring growth.

The trailing PE uses the last 12 months of actual EPS. The forward PE uses analyst estimates for the next 12 months. Forward PE is typically lower (assuming earnings grow), so always note which you are comparing.

S&P 500 PE Ratio History (1900–2026)

The long-run average PE for the S&P 500 since 1900 is approximately 15–17×. Here is how it has evolved through major market cycles:

The Shiller CAPE (Cyclically Adjusted PE) — which uses 10-year average inflation-adjusted earnings — provides a smoother, less volatile view. It has averaged ~17× historically and peaked at 44× in 2000. As of early 2026, the CAPE sits above 35×, well above its historical mean.

Current Market PE vs. Historical Average

As of March 2026, the S&P 500 trailing PE is approximately 26–28× — about 60–70% above the 100-year historical average of ~16×. This does not necessarily mean a crash is imminent (markets can stay elevated for years), but it does imply:

• Lower forward returns are likely over the next decade compared to periods of low valuations
• A higher bar for earnings growth to justify current prices
• More vulnerability to interest rate increases (higher rates compress PE multiples)

Interest rates are the key modifier. When the 10-year Treasury yields 5%, investors can earn 5% risk-free, making equities less attractive at high PE ratios. When rates are near zero (as in 2020–2021), even a 30–40× PE can be rationalized. Today's 4.5% rate environment puts downward pressure on sustainable PE multiples.

PE Ratios by Sector

"A good PE" is always relative to industry. High-growth technology companies should trade at higher PEs than mature utilities. Here are typical PE ranges by sector:

How to Use PE Ratio in Practice

1. Compare to the stock's own history

The most reliable signal is a stock trading at a discount to its own historical average PE. If Apple historically trades at 25–30× earnings and is currently at 20×, that suggests relative value — assuming the business quality has not deteriorated.

2. Compare to sector peers

A bank at 8× PE is not necessarily cheap if all banks trade at 10× and it has higher credit risk. Always benchmark against direct competitors.

3. Adjust for growth — use the PEG ratio

The PEG ratio = PE / Expected earnings growth rate. A rule of thumb: PEG below 1.0 may be undervalued; above 2.0 may be expensive. A company with a 30× PE growing at 30%/yr (PEG = 1.0) can be more attractive than a 12× PE company growing at 3%/yr (PEG = 4.0).

4. Watch for earnings quality

A low PE can be a value trap if earnings include one-time items, rely on accounting adjustments, or are about to decline. Always look at free cash flow alongside net income — the PE equivalent using FCF is the Price/FCF ratio.

5. Use multiple timeframes

Compare trailing PE, forward PE, and 5-year average PE side-by-side. If forward PE is significantly below trailing PE, analysts expect strong earnings growth — but verify that consensus is realistic.

Limitations of the PE Ratio

• Meaningless for negative earnings. Loss-making companies have no PE. Use Price/Sales or EV/EBITDA instead.
• GAAP distortions. One-time write-offs, goodwill impairments, or tax benefits can make earnings noisy. Use adjusted or normalized EPS.
• Sector blind. Never compare a bank's PE to a SaaS company's PE — the business models and capital structures are completely different.
• Ignores the balance sheet. Two companies with the same PE can have very different debt loads. EV/EBITDA (enterprise value to EBITDA) is often a better apples-to-apples comparison.
• Backward-looking. Trailing PE uses past earnings; what matters is future earnings power. Use forward PE and PEG to incorporate growth expectations.

Bottom Line: What Is a Good PE Ratio in 2026?

There is no universal "good" PE. But as a practical guide:

• For the S&P 500 as a whole, below 16× is historically cheap; above 25× is historically expensive (from a starting-point return perspective)
• For individual stocks, compare to their own 5-year historical PE range and sector peers
• Always adjust for growth (PEG) and interest rates — a 25× PE makes more sense when rates are 1% than when they are 5%
• Use PE as one input in a multi-factor framework, not as a sole buy/sell signal