# P/E Ratio Explained: Formula, Example & Interpretation

> The price-to-earnings (P/E) ratio measures how much investors pay for each dollar of a company's earnings. It's the share price divided by earnings per share. A P/E of 20 means you pay $20 for every $1 of annual profit. On its own it's just a number — its meaning comes from comparing it to the company's own history and its sector peers.

## Formula

**P/E Ratio = Share Price ÷ Earnings Per Share (EPS)** — Trailing P/E uses the last 12 months' EPS; forward P/E uses estimated future EPS.

## How to calculate

1. **Find the share price** — Take the current market price of one share.
2. **Find EPS** — Take earnings per share — net income divided by shares outstanding, over the last 12 months (trailing) or estimated (forward).
3. **Divide** — Divide the share price by EPS. The result is the P/E ratio.

## Worked example

A stock trades at $150 and earned $6.00 in EPS over the last year. Its P/E = 150 ÷ 6 = 25. Investors are paying $25 for each $1 of earnings. If its sector median is 18 and its own 10-year average is 20, this stock looks relatively expensive today.

## Interpretation

P/E level Often signals But check Low (below sector/history) Potential bargain or slow growth Is it cheap for a reason? (declining earnings) Average Fairly valued vs. peers Growth relative to price (see PEG) High (above sector/history) High growth expectations priced in Can growth justify the premium? Negative / N/A Company had no earnings (a loss) Use other metrics (P/S, FCF) The golden rule: never judge a P/E in isolation. A 30 P/E is cheap for a fast grower and expensive for a utility. Always anchor to the sector and the stock's own history.

## Limitations

- Meaningless for unprofitable companies (negative or no EPS).
- Earnings can be distorted by one-off items; a single quarter can mislead.
- Ignores debt and capital structure — ROE and EV/EBITDA add context.
- High-growth companies routinely carry high P/Es that a simple reading calls "expensive."

## FAQ

**What is a good P/E ratio?** There's no universal number. A P/E of 15–20 is typical for mature companies, while growth stocks may trade at 25–50+. What matters is the P/E relative to the company's sector and its own history, not an absolute threshold.

**What does a high P/E mean?** A high P/E means investors expect strong future earnings growth and are willing to pay a premium today. It can signal a quality growth company — or an overvalued one if that growth fails to materialize.

**What is the difference between trailing and forward P/E?** Trailing P/E uses actual earnings from the last 12 months; forward P/E uses analysts' estimated earnings for the next 12 months. Forward P/E reflects expectations but depends on the accuracy of those estimates.

## Related metrics

- PEG Ratio (/learn/peg-ratio)
- EPS (/learn/eps)
- How to Analyze Stocks (/learn/how-to-analyze-stocks)

See P/E for any stock free: https://foliofundamentals.com/analyzer