Price-to-Earnings in Practice
The price-to-earnings ratio is the most quoted valuation number in investing. Used well, it tells you how much optimism is built into a stock. Here is how to read trailing and forward P/E, what earnings yield means and when P/E misleads.
The basic idea
P/E is the share price divided by earnings per share. A stock at $100 earning $5 a share has a P/E of 20: investors pay $20 for each $1 of yearly profit. A higher P/E means the market expects faster growth or steadier profits; a lower one means lower expectations or more risk.
P/E: how many dollars investors pay for each dollar of yearly earnings.
Trailing vs. forward
Trailing P/E uses the last 12 months of actual earnings. Forward P/E uses analysts’ estimates for the next 12 months. When earnings are expected to grow fast, the forward P/E is much lower than the trailing one.
| Company | Trailing P/E | Forward P/E |
|---|---|---|
| NVIDIA (NVDA) | About 26.7 | About 13.5 |
| Microsoft (MSFT) | About 28.2 | About 21.4 |
| Apple (AAPL) | About 38.2 | About 34.8 |
| JPMorgan (JPM) | About 15.0 | About 14.0 |
| AT&T (T) | About 8.7 | About 10.3 |
| Tesla (TSLA) | About 326 | About 166 |
In our data as of Sept. 17, 2026. Forward figures depend on estimates that can be wrong.
Earnings yield: P/E flipped
Divide 1 by the P/E and you get the earnings yield. A P/E of 20 is an earnings yield of 5%; a P/E of 10 is 10%. This makes it easy to compare a stock with a bond or savings rate. If a stock’s earnings yield is below what a safe Treasury pays, you are counting on growth to make up the difference.
When P/E misleads
- Losses: companies with no earnings have no meaningful P/E.
- One-time items can inflate or shrink earnings for a year.
- Cyclical companies often look cheapest at the peak of their cycle, when earnings are temporarily high.
- Different industries carry different normal P/Es, so compare peers.
Key takeaways
- P/E = price ÷ earnings per share.
- Forward P/E uses estimates; trailing uses actual results.
- Earnings yield = 1 ÷ P/E.
- P/E misleads for losses, one-time items and cyclical peaks.