The P/E Ratio Explained: How to Project a Stock Price
What the price-to-earnings (P/E) ratio really means, how to use it to project a future stock price, and how it signals whether a stock is cheap or expensive.
What the P/E ratio is
Where EPS comes from
EPS vs. the P/E ratio: what’s the difference?
How to calculate the P/E ratio, step by step
Trailing vs. forward P/E
What counts as a “good” P/E?
The PEG ratio: P/E adjusted for growth
How to project a price target with P/E
Why test a range (bear / base / bull)
Limitations to remember
What’s a good P/E ratio by sector?
What a negative or “N/A” P/E means
P/E vs. earnings yield (and interest rates)
Common questions about the P/E ratio
Try it on a stock: Apple Inc. (AAPL) · MICROSOFT CORP (MSFT) · Alphabet Inc. (GOOGL) · NVIDIA CORP (NVDA) · AMAZON COM INC (AMZN) · Tesla, Inc. (TSLA) · Meta Platforms, Inc. (META)
Frequently asked questions
What is the P/E ratio?
The P/E ratio is the share price divided by earnings per share. It tells you how much investors pay for each dollar of a company’s annual profit — a P/E of 20 means $20 paid per $1 of earnings — and it is the most common shorthand for whether a stock looks cheap or expensive.
What is the P/E multiplier?
The P/E multiplier is another name for the P/E ratio: the multiple of earnings the share price represents. A stock at a 25x P/E multiplier trades at 25 times its annual earnings per share — identical math to the P/E ratio, different label.
What is a good P/E ratio for a stock?
There is no universal good P/E — it depends on growth and the sector. Fast-growing companies often trade at 25–40x earnings, while slow growers sit near 10–15x. Compare a stock’s P/E to its own 5-year average and to close peers rather than to a fixed number.
How do you calculate the P/E ratio?
Divide the current share price by earnings per share (EPS) over the last 12 months. A $100 stock earning $5 per share has a P/E of 20, meaning investors pay $20 for every $1 of annual earnings.
What does a negative P/E ratio mean?
A negative P/E means the company lost money over the last 12 months — the “E” is negative. The ratio is meaningless for valuation in that case; use cash-flow or revenue-based models instead.