What Is the P/E Ratio and How to Use It

Short answer: The price-to-earnings (P/E) ratio compares a stock's price to its earnings per share, giving a rough sense of how expensive the stock is relative to its profits.

How It Is Calculated

The P/E ratio is the share price divided by earnings per share (EPS). A P/E of 20 means investors are paying ₹20 for every ₹1 of annual earnings. It tells you, very roughly, how many years of current earnings you are paying for.

Trailing vs Forward P/E

Trailing P/E uses past 12-month earnings, while forward P/E uses estimated future earnings. Forward P/E reflects expectations but depends on forecasts that may be wrong. Always note which one you are looking at.

Why Context Matters

A P/E number means little in isolation. A high P/E may signal that the market expects strong growth, or that the stock is overvalued. A low P/E may signal a bargain, or a struggling business. Compare a company's P/E to its own history, to peers in the same industry, and to the broader market.

Limitations to Watch

P/E can be distorted by one-off profits or losses, by accounting choices, and by cyclical earnings. Loss-making companies have no meaningful P/E at all. For such cases, other metrics like price-to-sales or price-to-book may be more useful.

Pair It With Other Measures

Use P/E alongside earnings growth (the PEG ratio adjusts for growth), debt levels, return on equity, and cash flow. A holistic view prevents you from buying a cheap-looking but deteriorating business.

Practical Use

Treat P/E as a starting screen, not a verdict. Ask why a stock is cheap or expensive, and study the underlying business before deciding. Valuation is about the full picture, not a single number.

This explainer was written by The Dispatch desk to answer a question readers commonly ask. It is general information, not personalised financial advice.