P/E (Price-to-Earnings) Ratio Calculator

About P/E (Price-to-Earnings) Ratio Calculator

How the PE Ratio Is Calculated

The core formula is: PE Ratio = Share Price / Earnings Per Share (EPS). An equivalent company-level version is PE = Market Capitalisation / Net Income. Both produce the same number.

Worked example (per-share): A stock trades at $150 with trailing twelve-month EPS of $6.50. PE = 150 / 6.50 = 23.08. That means investors pay $23.08 for every dollar of annual profit. The earnings yield - the inverse - is 6.50 / 150 = 4.33%, which you can compare directly against bond yields or savings rates.

Worked example (company-level): A firm has a market cap of $2 billion and net income of $100 million. PE = 2,000,000,000 / 100,000,000 = 20.0. This is useful when EPS is not readily available, or when comparing companies with different share counts.

There are two common versions of PE. Trailing PE uses the last 12 months of reported earnings. Forward PE uses analyst consensus estimates for the next 12 months. Forward PE is generally lower because analysts expect earnings to grow, but it carries the risk that estimates may prove wrong. This calculator uses whichever earnings figure you provide - just be consistent when comparing stocks.

What Is a Normal PE Ratio?

The S&P 500 trailing PE was approximately 25.1 as of April 2026 (GuruFocus). The 20-year median sits around 16.5, so the current market trades at a significant premium to its long-run average. The Shiller CAPE ratio - which smooths earnings over 10 years to remove cyclical distortion - stood at roughly 40.2 in April 2026 (Multpl.com), the second-highest reading in over 140 years of data behind the dot-com peak of 44.2 in December 1999.

These elevated multiples partly reflect the growing weight of high-margin technology companies in the index. Low real interest rates through much of the 2010s and early 2020s also pushed investors toward equities, compressing the equity risk premium and inflating PE multiples across the board.

PE Ratio by Sector

PE ratios vary widely across industries because different sectors have different growth profiles, capital intensity, and earnings volatility. The table below shows typical forward PE ranges by S&P 500 sector as of early 2026 (MacroMicro, Damodaran/NYU Stern).

Sector	Forward PE Range	Why
Information Technology	22 - 35	High growth expectations, scalable margins
Healthcare	18 - 30	Drug pipelines, patent cliffs create wide spread
Financials	12 - 18	Cyclical earnings, regulated capital
Utilities	14 - 20	Stable cash flows, slow growth
Consumer Staples	18 - 25	Defensive, steady demand
Energy	10 - 16	Commodity-driven, volatile earnings
Real Estate (REITs)	25 - 45	Depreciation depresses reported EPS
Industrials	16 - 22	Moderate growth, economic sensitivity

Comparing a company's PE only to its own sector is far more informative than comparing against the overall market. A technology stock at 28x may be cheap relative to peers, while a utility at 28x would be extremely expensive. Use the price-to-sales ratio as a companion metric when PE alone does not tell the full story - particularly for high-reinvestment companies with depressed current earnings.

Earnings Yield and the Bond Comparison

Earnings yield is simply 1 / PE, expressed as a percentage. A stock with a PE of 25 has an earnings yield of 4.0%. This lets you make a rough comparison to risk-free rates: if the US 10-year Treasury yields 4.3%, a stock earning 4.0% on a PE basis needs to offer growth or diversification benefits to justify the extra risk. The gap between earnings yield and the risk-free rate is sometimes called the equity risk premium.

When earnings yields were well above bond yields (as they were through much of 2010 to 2021), the case for equities was straightforward. With bond yields rising since 2022 and earnings yields compressed by high PE multiples, the gap has narrowed considerably. Monitoring this relationship is one practical use for the earnings yield figure this calculator provides. You can track bond yields alongside equity returns using the bond yield calculator.

The PEG Ratio - Adjusting PE for Growth

Peter Lynch popularised the PEG ratio in his 1989 book "One Up on Wall Street." The formula is: PEG = PE Ratio / Expected Annual EPS Growth Rate. Lynch argued that a fairly valued company should have a PEG of roughly 1.0 - meaning its PE equals its growth rate.

Worked example: A stock trades at a PE of 30 with expected annual EPS growth of 25%. PEG = 30 / 25 = 1.20. Under Lynch's framework, this is close to fairly valued. A PEG below 1.0 suggests the stock may be undervalued relative to its growth, while a PEG above 2.0 suggests the market may be pricing in unrealistic growth expectations.

PEG Range	Interpretation	Typical Action
Below 0.5	Deeply undervalued (if growth is real)	Strong buy signal - verify growth estimate
0.5 - 1.0	Potentially undervalued	Attractive if fundamentals support growth
1.0 - 1.5	Fairly valued	Hold or buy on dips
1.5 - 2.0	Getting expensive	Needs strong catalyst to justify entry
Above 2.0	Potentially overvalued	Growth expectations may be too optimistic

The main weakness of PEG is that it relies on growth estimates, which are inherently uncertain. Analyst consensus can shift quickly after an earnings miss or macro shock. Lynch himself filtered for companies with 15% to 30% earnings growth over the prior five years and insisted on a debt-to-equity ratio below 0.6. PEG works best as one input alongside other valuation tools, not as a standalone buy/sell signal.

When PE Ratio Breaks Down

PE is meaningless for companies with zero or negative earnings, because you either divide by zero or get a negative number that has no useful interpretation. Loss-making firms - common in biotech, early-stage tech, and cyclical downturns - need alternative metrics. The enterprise value calculator using EV/Revenue or EV/EBITDA is often more appropriate in those cases.

Several other situations can distort PE:

• One-time charges: A large write-down or restructuring cost can depress a single year's earnings, inflating the PE temporarily. Using normalised or forward earnings helps avoid this trap.
• Stock-based compensation: Tech companies often pay employees in equity, which dilutes EPS. Adjusted earnings that add back SBC will show a lower PE than GAAP earnings.
• Cyclical peaks and troughs: A mining company at the top of a commodity cycle may have a very low PE because earnings are temporarily elevated. Buying at a low PE can actually mean buying at the worst time if earnings are about to fall.
• Accounting differences: IFRS and US GAAP treat items like R&D capitalisation, lease accounting, and pension obligations differently. Cross-border PE comparisons need care.
• REITs and MLPs: Real estate investment trusts report large depreciation charges that reduce EPS below actual cash generation. Funds from operations (FFO) is a better metric for REITs than PE.

The Shiller CAPE Ratio

Nobel laureate Robert Shiller developed the cyclically adjusted PE ratio (CAPE) to address the problem of earnings volatility. Instead of one year of earnings, CAPE uses the average of inflation-adjusted earnings over the past 10 years. This smooths out business cycles and gives a more stable picture of long-term valuation.

The historical median CAPE for the S&P 500 is approximately 16.1 (Multpl.com). As of April 2026, CAPE sits near 40 - roughly 2.5 times the long-run median. Research by Shiller and others has shown that high CAPE values tend to predict lower long-term equity returns over the following 10 years, though CAPE has limited power for timing shorter-term market moves. It is most useful as a gauge of whether the overall market is historically cheap or expensive, not as a trigger for buying or selling individual stocks.

Practical Tips for Using PE Ratios

Compare within the same sector. A PE of 30 is cheap for cloud software but expensive for a regional bank. Always check what type of earnings the PE is based on - trailing, forward, GAAP, or adjusted - because mixing types leads to bad comparisons. Combine PE with at least one other metric: dividend yield for income stocks, EV/EBITDA for capital-intensive firms, or price-to-sales for high-growth companies that reinvest all profits.

Watch for PE compression during rising interest rate environments. Higher rates increase the discount rate applied to future cash flows, which typically pushes PE multiples down even if earnings hold steady. Conversely, falling rates tend to expand multiples. This rate sensitivity is one reason the overall market PE rose so sharply during the low-rate era of 2010 to 2021 and has fluctuated more since central banks began tightening in 2022.

For a quick sanity check, use the "Rule of 20" - if PE plus the inflation rate exceeds 20, the market is considered overpriced by this heuristic. With S&P 500 PE near 25 and US CPI inflation at 3.3% as of March 2026 (Bureau of Labor Statistics), the sum is roughly 28.3, well above the threshold. This does not mean you should sell everything, but it does suggest that forward returns may be lower than the historical average of roughly 10% per year. Pair PE analysis with the stock average calculator to track your cost basis and see how valuation multiples affect your personal returns over time.

Sources

• Investopedia - Price-to-Earnings (P/E) Ratio definition
• Multpl - Shiller PE Ratio (CAPE) historical data
• Robert Shiller - Online Data (CAPE methodology)
• SEC - Earnings Per Share (EPS) definition
• US Bureau of Labor Statistics - Consumer Price Index (CPI)
• Corporate Finance Institute - Price-Earnings Ratio