Price to Earnings Calculator

Price to Earnings Calculator: calculate price to earnings for your business. Formula, benchmarks, and practical tips included.

The price-to-earnings (P/E) ratio measures how many times a company's current share price represents its earnings per share — essentially how much investors are paying for each unit of profit. A P/E of 20 means investors pay 20 for every 1 of annual earnings. P/E is the most widely quoted equity valuation metric in financial media and is used to compare stocks against each other, against their historical ranges, and against market averages. However, it is only meaningful in context — growth rate, interest rates, and sector all fundamentally affect what P/E is "appropriate". Profit Margin Calculator and Markup Calculator provide complementary valuation perspectives.

Enter current share price and earnings per share (EPS) — trailing EPS (last 12 months) for trailing P/E; consensus forecast EPS for forward P/E.
P/E = Share price ÷ Earnings per share.
Compare trailing P/E, forward P/E, and PEG ratio (P/E ÷ expected growth rate).
PEG ratio normalises P/E for growth — a PEG below 1.0 is often considered potentially undervalued; above 2.0 may be expensive relative to growth.
Compare against sector median P/E, market average P/E, and historical P/E range for the same stock.

P/E ratio formulas

P/E = Share price ÷ Earnings per share (EPS)

Trailing P/E = Price ÷ Last 12 months EPS

Forward P/E = Price ÷ Next 12 months consensus EPS estimate

PEG ratio = P/E ÷ Expected earnings growth rate %

Worked example: Share price 45. Trailing EPS 2.25. Trailing P/E = 45/2.25 = 20×. Forward EPS estimate 2.70. Forward P/E = 45/2.70 = 16.7×. Expected growth rate 15%. PEG = 16.7/15 = 1.11 — modestly valued relative to growth rate.

Interpreting P/E ratios

Historical and sector P/E benchmarks

Historical context: The long-run average trailing P/E for major indices (S&P 500, MSCI World) is approximately 15–17×. During low interest rate periods (2013–2021), average P/Es expanded to 20–25×. During high rate periods, P/Es compress. Sector ranges (2024): utilities 12–16×; banks 8–12×; consumer staples 18–23×; industrials 16–22×; healthcare 16–22×; technology 25–35×; high-growth SaaS often 50–100×+ on trailing earnings (if profitable). Loss-making companies cannot be valued on trailing P/E — use EV/Revenue or DCF instead.

Business tips and best practices

Use forward P/E for growing companies — trailing P/E reflects past earnings that may be unrepresentative of a company's future trajectory.
P/E is meaningless in isolation — a P/E of 25 may be cheap for a 30% grower but expensive for a 5% grower; always pair with PEG ratio and sector context.
Interest rates directly affect appropriate P/E levels — at 5% risk-free rates, a 20× P/E offers a 5% earnings yield which barely compensates for equity risk; at near-zero rates, 25–30× may be rational.

The S&P 500's P/E peaked at approximately 30× in early 2000 (dot-com peak) and approximately 37× in December 2020 (post-COVID stimulus); it fell to approximately 18× in October 2022 (rate-hike trough).
Stocks trading below a PEG ratio of 1.0 have historically outperformed the market on a 1–3 year basis in multiple studies, though this relationship is not guaranteed.

Common mistakes to avoid

Comparing P/E across different sectors — a bank at 10× P/E and a software company at 30× P/E cannot be meaningfully compared using P/E alone.
Using P/E for loss-making companies — when EPS is negative or near zero, P/E is mathematically meaningless; use EV/Revenue or gross profit multiples instead.

P/E ratios and other valuation metrics are analytical tools, not investment recommendations. Share prices can fall significantly below any calculated intrinsic value. Investment in equity securities carries risk, including the risk of total loss. Investment advice must be provided by a regulated adviser authorised in your jurisdiction. Historical valuation multiples do not guarantee future performance. This calculator is for educational purposes only.