P/E Ratio vs Historical Average Comparison

Compare the current P/E ratio to its historical average. See if the stock is overvalued or undervalued compared to its own history.

Current market price per share

Trailing 12-month EPS

Next 12 months expected EPS

5-10 year average P/E ratio

Lowest P/E in the period

Highest P/E in the period

Trailing P/E = Current Price / Trailing EPS\nForward P/E = Current Price / Forward EPS\nFair Value = Historical P/E × Current EPS\nUpside = (Fair Value - Current Price) / Current Price\nPremium = (Current P/E - Historical P/E) / Historical P/E
Price: $150 | EPS: $10 → P/E 15x\nHistorical Avg: 20x\n\nFair Value = $10 × 20 = $200\nUpside = ($200 - $150) / $150 = +33%\nPremium vs History = (15-20)/20 = -25%\n\nVerdict: Below historical P/E - potentially undervalued

What is the P/E ratio?

P/E (Price-to-Earnings) ratio measures how much you pay for each dollar of earnings. P/E of 20 means you pay $20 for $1 of earnings. Formula: Stock Price / EPS. A high P/E means investors expect high growth or are willing to pay premium. Low P/E means value opportunity or problems.

What is a "good" P/E ratio?

Context matters: (1) S&P 500 historical average = 15-20x, (2) Growth stocks = 25-50x, (3) Value stocks = 10-15x, (4) Tech/Growth = higher, (5) Banks/Utilities = lower. Compare to: industry average, historical own range, and expected growth. Never use P/E alone - a low P/E might indicate problems.

What does P/E vs historical average tell you?

Comparing current P/E to historical average shows if stock is expensive relative to its own history. Trading at 30x when it normally trades at 20x suggests premium or overvaluation. Conversely, 15x when normally 20x might be value. But verify why: is growth expected to accelerate, or is the premium justified?

What is the difference between trailing and forward P/E?

Trailing P/E uses ACTUAL past 12 months earnings (real, confirmed). Forward P/E uses EXPECTED next 12 months earnings (projections). Forward P/E tells you what investors expect. If forward P/E < trailing P/E, earnings are expected to grow. If forward P/E > trailing, earnings expected to decline.

What is PEG ratio?

PEG (Price/Earnings-to-Growth) ratio = P/E divided by expected earnings growth rate. PEG of 1 = fairly valued. PEG < 1 = potentially undervalued (low price relative to growth). PEG > 1 = potentially overvalued (paying premium for growth). Example: P/E 20, growth 10% = PEG 2 (expensive). P/E 15, growth 15% = PEG 1 (fair).

Why is earnings yield useful?

Earnings Yield = Earnings/Price = 1/P/E. While P/E shows "price per $1 earnings," yield shows "earnings per $100 invested." Compare to: bond yields (4-5%), savings (4%), inflation (3%). If earnings yield 7% and bond yield 5%, stocks are relatively attractive. Useful for comparing stocks to bonds.

When is a low P/E a red flag?

Low P/E can indicate: (1) Business decline (earnings falling), (2) One-time write-offs skewing EPS, (3) Cyclical industry at peak, (4) Debt problems, (5) Legitimate value opportunity. Always check: earnings trend, debt levels, competitive position, industry headwinds. "Cigar butts" can become worthless.

What P/E should I pay for a stock?

Depends on: growth rate (faster = higher), stability (stable = higher), industry (tech = higher, banks = lower), interest rates (low rates = higher). Rule of thumb: P/E roughly equal to growth rate for reasonable value. 15% growth = 15 P/E. Add premium for exceptional franchises, discount for risk. But don't pay >30x unless exceptional.