Price-to-earnings ratio is the stock price divided by earnings per share. It tells you how much investors pay for $1 of annual earnings. P/E of 20 means $20 paid for every $1 of EPS. Lower P/E = cheaper relative to earnings; higher = more expensive (or higher growth expected).

How is P/E ratio calculated?

P/E = Stock Price / Earnings Per Share (EPS). Stock price is current market price. EPS is net income divided by shares outstanding (or use diluted EPS for fully-diluted comparison). Trailing P/E uses past 12 months EPS; forward P/E uses next 12 months estimates.

What is a good P/E ratio?

Depends on industry, growth, interest rates, and market conditions. Historical S&P 500 average is ~16. Tech sector often 25-35. Banks/utilities 10-15. Below 10: value or distressed. Above 30: high growth or speculative. Always compare to industry peers and growth rate.

Trailing vs forward P/E?

Trailing P/E uses past 12 months earnings (TTM) — actual reported numbers. Forward P/E uses analyst estimates for next 12 months — forward-looking but unreliable. Use trailing for established companies; forward for growth companies or recovery situations.

What is the PEG ratio?

PEG = P/E / Annual Growth Rate. It adjusts P/E for growth — a high P/E is justified if growth is high. PEG 1.5 = potentially overvalued. PEG > 2 = expensive.

What is earnings yield?

Earnings yield = 1 / P/E × 100. It's the inverse of P/E expressed as a percentage. A P/E of 20 = 5% earnings yield. Useful for comparing stocks to bonds: if 10-year Treasury yields 4% and a stock has 6% earnings yield, the stock is more attractive on yield alone.

What does negative P/E mean?

Negative P/E means the company has negative earnings (losses). The ratio is undefined or negative — meaningless for valuation. Use other metrics like price-to-sales (P/S), price-to-book (P/B), or EV/EBITDA for unprofitable companies. Most growth-stage companies have negative P/E.

Why is Tesla's P/E so high?

High P/E reflects investor expectations of future earnings growth. Tesla's 50-100 P/E during high-growth years priced in years of expected expansion. If actual growth meets expectations, the high P/E is justified. If not, the stock corrects sharply. High-P/E stocks have higher upside AND downside.

P/E Ratio Calculator

The P/E ratio is the most widely used stock valuation metric. It tells you how much investors are paying per dollar of earnings: a P/E of 20 means $20 paid for $1 of annual earnings. Trailing P/E uses past 12 months earnings; forward P/E uses next 12 months estimates. Lower P/E = value (or distressed); higher P/E = growth premium. The PEG ratio (P/E divided by growth rate) accounts for growth — PEG under 1 is generally considered attractive.

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calendar_today Updated: April 2026

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monitoringStock Valuation

Stock Price

EPS

Industry Avg P/E (optional)

Growth Rate %

analyticsValuation Metrics

P/E Ratio

25.00

Growth

Above average P/E — growth premium

Earnings Yield

4.00%

PEG Ratio

—

vs Industry

—

Input Values

Stock Price

Earnings Per Share (EPS)

P/E Type

Trailing (past 12 months)

Forward (next 12 months)

tips_and_updates Tips

• Compare P/E to industry average and historical range
• Trailing P/E uses past earnings; forward P/E uses estimates
• Low P/E (under 10) = value or distressed
• Average P/E (10-20) = mature companies
• High P/E (20-30+) = growth premium
• PEG under 1.0 = potentially undervalued growth
• Negative earnings make P/E undefined — use other metrics
• S&P 500 historical average P/E: ~16; current swings 18-25

How to Use This Calculator

Enter stock price

Current market price per share.

Enter EPS

Annual earnings per share.

Choose P/E type

Trailing (actual) or forward (estimated).

Optional: industry P/E + growth

For peer comparison and PEG ratio.

Review valuation

P/E + interpretation + category.

The Formula

P/E doesn't tell you if a stock is cheap or expensive in isolation — you must compare it to history, industry peers, growth rate, and interest rates. A 30 P/E is cheap for a 50% grower but expensive for a 5% grower. Always look at PEG and industry context.

P/E Ratio = Stock Price / Earnings Per Share (EPS)

lightbulb Variables Explained

P/E Years of earnings to recoup investment at current price
EPS Earnings per share — net income / shares outstanding
Earnings Yield 1/PE × 100 = inverse of P/E, like a bond yield
PEG P/E / Annual Growth Rate — adjusts for growth

tips_and_updates Pro Tips

Compare P/E to industry average and historical range

Trailing P/E uses past earnings; forward P/E uses estimates

Low P/E (under 10) = value or distressed

Average P/E (10-20) = mature companies

High P/E (20-30+) = growth premium

PEG under 1.0 = potentially undervalued growth

Negative earnings make P/E undefined — use other metrics

S&P 500 historical average P/E: ~16; current swings 18-25

Frequently Asked Questions

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