Price to Earnings Ratio Calculator: P/E From Price and EPS

Work out a stock's price to earnings (P/E) ratio — the most widely cited single number in equity investing, and the quickest way to spot whether a share is priced for value or for growth.

Amount & Quantity
$
Current share price.
Trailing twelve-month EPS for trailing P/E, or analyst estimates for forward P/E.
Your estimate $—

Adjust the inputs and select Calculate for a full breakdown.

Compare Common Scenarios

How the numbers shift across typical situations for this calculator:

ScenarioP/E ratio (price per $1 of earnings)
$50 price · $2.50 EPS$20.00
$120 price · $4.00 EPS$30.00
$30 price · $0.80 EPS$37.50
$200 price · $5.50 EPS$36.36

How This Calculator Works

Enter the current share price and the company's earnings per share (EPS). The calculator divides one by the other to give the P/E ratio — read it as the dollars you are paying for each $1 of annual earnings.

The Formula

Cost per Unit

Unit Cost = Total Amount / Quantity

Total Amount is the full cost or price, Quantity is the number of units it covers

Worked Example

A stock trading at $50 with $2.50 of EPS has a P/E of 20 — investors are paying $20 today for every $1 of current annual earnings. The S&P 500 has averaged a P/E between 15 and 18 across long periods; growth stocks routinely trade above 30; mature value stocks below 12.

Key Insight

P/E is a price-relative-to-now metric. A high P/E means the market expects future earnings to be much higher; a low P/E suggests either declining expectations or undervaluation. P/E alone is never a buy or sell signal — pair it with growth rate (PEG ratio), debt levels, and industry comparable to interpret the figure correctly.

CAPE — Shiller's smoothed P/E for the long view

Robert Shiller's CAPE (Cyclically Adjusted P/E) uses average inflation-adjusted earnings over 10 years instead of trailing or forward 1-year earnings. The 10-year average smooths out business cycle distortions — a recession year's low earnings don't make a stock falsely cheap; a peak year's high earnings don't make it falsely expensive.

Long-run U.S. CAPE history: average ~17, range 5 (1920) to 44 (1999 dot-com peak). 2024 CAPE: ~34, second-highest in history after 1999. This signals expensive valuations historically — every prior period above CAPE 30 has been followed by 10-year forward returns of 0-5% real (well below long-run 7%).

Critique of CAPE: (1) accounting changes (goodwill impairments, R&D expensing, stock-based compensation) have made today's GAAP earnings less comparable to 1950s-1980s earnings; (2) low interest rates justify higher P/E ratios (lower discount rate raises present value); (3) sector composition has shifted to high-margin tech and consumer brands that warrant higher multiples than 1950s industrials. The 'true' fair-value CAPE may be 22-26 rather than 17 — making current 34 still expensive but not as extreme as raw comparison suggests.

Why tech P/E is structurally higher than utility P/E

P/E ratios vary across industries because growth rates, capital intensity, and risk profiles differ. Tech P/E (typical 25-40 for software / SaaS) is high because: (1) low capital requirements mean earnings can grow rapidly without proportional reinvestment; (2) network effects produce winner-take-most dynamics with high margins; (3) growth optionality is valuable. Utility P/E (typical 15-20) is low because: (1) heavy capital requirements limit growth; (2) regulated returns cap upside; (3) stable cash flows are easier to value but offer less upside.

Damodaran's annual sector data: median 2024 P/E by sector — Software 35; Pharma 22; Banks (regional) 13; Retail 18; Utilities 18; Real Estate (REITs) 20 (vs FFO, not earnings); Energy 14; Industrials 20. Cross-sector P/E comparison is economically meaningless without adjusting for growth, capital intensity, and risk.

Within sectors, P/E spreads can be 2-3×. Within software, growth-stage companies trade at 30-50× while mature lower-growth software (Oracle, IBM) trades at 15-20×. The right comparison is to the closest possible peer set — same sector, same growth rate, same capital structure. Pure P/E comparison across companies without controlling for these factors produces consistently wrong investment conclusions.

U.S. P/E benchmarks by sector and time period

Reference P/E ratios for U.S. equities. Historical CAPE smooths business cycle distortions.

MetricCurrent (~2024)Long-run averageNotes
S&P 500 trailing P/E~25~16Tech-weighted; current high
S&P 500 forward P/E~22~15Based on estimates
S&P 500 CAPE (Shiller)~34~1710-yr smoothed; very high
Software / SaaS30-45~25Growth premium
Pharma (large branded)18-25~20
Banks (large diversified)10-13~13Cyclical discount
REITs (vs FFO)18-25~20Income-oriented
Utilities16-20~17Income-oriented
Energy (oil majors)10-15~14Cyclical

Forward P/E uses analyst estimates which historically have been ~10% too optimistic on average. The 'real' forward P/E is typically ~10% higher than what's quoted. CAPE remains the most reliable long-run valuation indicator despite its accounting-comparability limitations.

Frequently Asked Questions

How is P/E ratio calculated?

Divide the current share price by earnings per share. A $50 stock with $2.50 EPS has a P/E of 20.

What is trailing vs forward P/E?

Trailing P/E uses the past twelve months of EPS — backward looking and verified. Forward P/E uses analyst estimates for the next twelve months — forward looking but less certain.

What is a good P/E ratio?

It depends on the sector and the company's growth. Mature businesses commonly trade at 10 to 18; growth companies often 25 to 50; some hyper-growth names well above that. Compare against industry peers, not market averages.

Why do some stocks have no P/E?

Because they have no earnings — either they are loss-making or earnings are negligible. Many high-growth tech companies trade at sky-high or undefined P/E for years; revenue multiples are often used instead.

How is P/E related to dividend yield?

Inversely correlated for mature payers. A higher P/E generally means a lower yield because dividends grow more slowly than the share price. Yield-focused investors often hunt at lower P/E ratios.

When is this calculator unreliable?

For companies with negative or near-zero earnings (P/E becomes undefined or extreme — use price-to-sales or price-to-book instead), when earnings are temporarily distorted by one-time items (use normalized 3-5 year average earnings or operating earnings), when comparing across sectors with different growth and capital characteristics (cross-sector P/E comparison is economically meaningless without adjustment), or as a stand-alone metric without growth context (PEG ratio = P/E divided by growth rate provides growth-adjusted comparison).

References & Authoritative Sources

Related Calculators

Data Sources & Benchmarks

This calculator draws on 1 independent, dated source.

10.30% Provisional
S&P 500 long-run annual return
S&P 500 Index — Long-Run Annualized Total Return
S&P Dow Jones Indices · as of December 31, 2025
View source ↗

Methodology & Review

Ugo Candido ✓ Editor
Founder & Editor-in-Chief at CalcDomain — responsible for the methodology, sourcing, and technical review of this calculator.

Price-to-earnings ratio (P/E) equals stock price / earnings per share. The calculator returns the P/E ratio. Two main variants: trailing P/E uses past 12 months earnings (most reliable); forward P/E uses next 12 months earnings (more forward-looking but depends on analyst estimates). Historic S&P 500 average P/E: ~16; long-run range 7-30. Higher P/E indicates higher growth expectations or lower required return; lower P/E indicates concerns about future earnings or high required return. RELIABILITY: Reliable as a current-period valuation metric. Less reliable for companies with negative or near-zero earnings (P/E becomes undefined or extremely volatile), for comparing across very different industries (tech, banking, utilities, REITs have structurally different P/E ranges), when earnings are temporarily depressed by one-time items (use normalized earnings), or as a stand-alone valuation indicator without considering growth (high-growth companies justify higher P/E; PEG ratio adjusts for this).

Updated