The price-to-earnings ratio — usually written as P/E or PE — is the single most-quoted number in Indian stock research. It appears on every stock page, gets cited by analysts on TV, and forms the basis of many buy/sell debates on social media. Yet most retail investors use it as a single-number verdict on whether a stock is "cheap" or "expensive" without understanding what it actually measures.
This guide explains what PE ratio is, what it's not, and how to use it in the Indian market specifically.
What PE Ratio Actually Measures
PE ratio is one number divided by another:
PE = Current Share Price / Earnings Per Share (EPS)
If TCS trades at ₹3,500 and its trailing 12-month EPS is ₹140, its PE ratio is 25 (₹3,500 ÷ ₹140). Read literally, this means: at the current price, you're paying ₹25 today for every ₹1 of annual earnings TCS produced last year.
Trailing PE — uses the last 12 months of actual reported earnings. Backward-looking, factual.
Forward PE — uses analyst estimates of the next 12 months' earnings. Forward-looking, dependent on consensus assumptions.
If Forward PE is meaningfully lower than Trailing PE, the market is pricing in earnings growth — analysts expect EPS to be higher next year than it was last year. If Forward PE is higher than Trailing PE, the market is pricing in an earnings drop.
What PE Doesn't Tell You
PE is a ratio, not a verdict. It says nothing about:
- How fast earnings are growing. A stock with PE 20 and 25% earnings growth is cheaper than a stock with PE 15 and 5% earnings growth — even though the second number is "lower".
- Whether the earnings are real. Companies can boost EPS temporarily through buybacks, accounting choices, or one-off gains. PE on those numbers misleads.
- Capital intensity. An IT services firm earning ₹100 cr with ₹50 cr in fixed assets is fundamentally different from a steel maker earning ₹100 cr with ₹5,000 cr in fixed assets — even at the same PE.
- Debt. PE uses equity earnings, so two companies with similar earnings can have very different risk profiles if one is heavily debt-funded.
Sector Matters — Hugely — in India
The single biggest mistake retail investors make is comparing PE across sectors. Indian sectors have wildly different "normal" PE bands because the underlying businesses are different.
| Sector | Typical PE Range | Why |
|---|---|---|
| FMCG (HUL, Nestle, Britannia) | 40-70 | Stable demand, high margins, brand moats — market pays a premium for predictability |
| IT Services (TCS, Infy) | 20-35 | Predictable cash flows, USD revenue, slower growth than 2010s |
| Private Sector Banks | 15-30 | Cyclical earnings tied to credit cycle |
| PSU Banks | 5-15 | NPA cycles, lower ROE, government ownership discount |
| Steel / Metals | 5-15 | Heavily cyclical, commodity-linked |
| Pharma | 20-40 | R&D-heavy, US FDA exposure, mixed generics + branded |
| Auto | 15-25 | Cyclical, demand-sensitive |
A PE of 50 is "expensive" for a steel company and "normal" for HUL. Comparing them is meaningless. Always benchmark a stock's PE against its sector peers, not the broader market.
The Three PE Mistakes to Avoid
1. "PE under 15 means cheap"
Wrong for most sectors. A PE of 8 might mean the market expects earnings to collapse next year — there's usually a reason. PSU banks have spent decades at PE under 10 because the market correctly priced in low growth and NPA risk. The ratio without the why is incomplete.
2. "PE over 40 means overvalued"
Equally wrong. Avenue Supermarts (DMart) listed in 2017 at PE 100+ and compounded earnings at 25%+ — the high PE was justified. If you'd dismissed it based on the multiple, you'd have missed a 5x return.
3. Comparing PE across cycles
A stock's PE during a boom year (when earnings are inflated) looks low even if the price is rich. The same stock during a downturn (when earnings are depressed) looks expensive on PE even when the price is reasonable. Cyclical stocks need to be valued on normalised earnings, not point-in-time EPS.
What to Look at Alongside PE
PE is one input, not a conclusion. The shorthand checklist that actually works for Indian stocks:
| Look At | Why |
|---|---|
| PE relative to sector median | Tells you if the stock is cheap/expensive within its peer set |
| Forward PE vs Trailing PE | Direction of expected earnings change |
| ROE | Quality of the earnings being valued. PE 25 on ROE 25% is very different from PE 25 on ROE 8% |
| 5-year earnings growth | Whether the company has actually grown — PEG ratio is just PE divided by growth |
| Debt-to-equity | Whether earnings are levered (and therefore riskier) |
| Sector cycle position | Are earnings near peak or trough? |
The PEG Ratio — PE Adjusted for Growth
The simplest improvement on raw PE is the PEG ratio:
PEG = PE / Earnings Growth Rate (%)
If a stock has PE 30 and earnings growing 30%, PEG is 1.0. If PE is 30 and growth is 10%, PEG is 3.0 — meaningfully more expensive on a growth-adjusted basis.
Rule of thumb: PEG below 1.0 is generally considered cheap; above 2.0 is generally considered expensive. But this is just a heuristic — quality, sector cycle, and capital intensity still matter.
Practical Workflow on VivaTrades
If you want to apply this in practice on Indian stocks:
- Start with a sector filter. Use the Explore page to find stocks within a single sector — say IT services or Banking. Comparing PE only makes sense within sectors.
- Compare PE to peers. On any stock page, the Peers section shows the stock's PE vs the sector average and its rank within peers.
- Check Forward PE. If Forward PE is materially lower than Trailing PE, the market expects growth. Cross-check with the analyst consensus shown on the stock page.
- Look at ROE. Same PE on a 25% ROE business is very different from the same PE on a 10% ROE business.
- Use the Compare tool. Side-by-side comparison of TCS vs INFY or HDFC Bank vs ICICI Bank lays out the metrics that matter for relative valuation.
Final Thought
PE ratio is a useful starting point. It is not a verdict. The investors who use PE well treat it as a "first question" — "why is this stock priced at this multiple of earnings?" — and then go look for the answer in growth rates, capital intensity, sector dynamics, and competitive positioning.
The investors who get burned by PE treat it as a "final answer" and act on the number alone. Don't be that investor.