Quick explanation: Sector valuation compares the market value of the companies in a sector with the earnings they generate. A sector's aggregate P/E is its combined market cap divided by its combined aligned earnings. Sector analysis helps you see which parts of the Nifty 50 account for most of its value, its profits and its movements.
A top-down framework
A useful research sequence is:
Start with the economic backdrop: growth, inflation, interest rates and global conditions. Then look at how the index is composed, which sectors matter most, which companies drive those sectors, what they earn, and what the market is paying for those earnings.
Use the official NSE sector classification applicable on the date of your analysis. Do not invent custom sector labels or silently move companies between categories; doing so makes your results impossible to compare with anyone else's.
Step 1: sector full market cap
Add up the full market caps of every constituent in the sector. This tells you how much market value the sector represents among the companies you are studying.
Step 2: sector earnings and aggregate P/E
Sector Aggregate P/E = Sector Full Market Cap ÷ Sector Earnings
"Aligned" means every company's earnings use the same period (FY, TTM or forward), the same basis (consolidated attributable profit is usually best) and the same treatment of exceptional items.
These are full-market-cap teaching formulas. Label any result accordingly; it is not automatically the same as an official index-provider sector P/E.
Completeness rule: if any company's earnings are missing, do not quietly drop it and report a sector P/E as if it were complete. Either fill the gap with a verified figure, or show the P/E as unavailable and say why.
Worked example: a hypothetical banking sector
| Bank | Full market cap (₹ Cr) | Annual attributable profit (₹ Cr) |
|---|---|---|
| Bank A | 2,00,000 | 10,000 |
| Bank B | 3,00,000 | 15,000 |
| Bank C | 1,00,000 | 5,000 |
| Total | 6,00,000 | 30,000 |
Here each bank happens to trade at 20×, so the average and the aggregate agree. They usually do not.
Why the average of P/Es misleads
Take two companies in the same sector, each with a market cap of ₹1,00,000 crore. Company X earns ₹10,000 crore (P/E 10×); Company Y earns ₹3,333 crore (P/E 30×).
Aggregate P/E = 2,00,000 ÷ 13,333 = 15×
The aggregate P/E answers the right question: what is the market paying for the sector's combined earnings? The simple average gives a high-P/E company with small earnings as much influence as a low-P/E company with large earnings, and a single company with tiny profits and a P/E in the hundreds can distort an average enormously. Always use combined market cap divided by combined earnings.
Sector share of the Nifty 50
Suppose the Nifty 50 companies have a hypothetical combined full market cap of ₹200 lakh crore, and the banks in the example have a combined full market cap of ₹6 lakh crore.
Important: this 3% is a share of combined full market cap, not the sector's official Nifty 50 index weight. Official weight needs each constituent's free-float market cap, which requires official IWF data.
From the dashboard snapshot. Applying these formulas to the indicative 13–15 October 2026 snapshot on our Nifty 50 sector dashboard gives, for example:
| Sector | Companies | Share of combined full cap | Full-cap aggregate P/E |
|---|---|---|---|
| Financial Services | 12 | 29.83% | 17.17× |
| Oil, Gas & Consumable Fuels | 3 | 11.56% | 14.18× |
| Information Technology | 4 | 9.67% | 16.09× |
| Fast Moving Consumer Goods | 4 | 6.18% | 31.30× |
| Services | 2 | 3.23% | Not available — incomplete earnings |
These are derived from a supplied, mixed-date historical snapshot, using earnings implied from reported P/E. They are not audited profits, official sector P/Es or official index weights, and they are not recommendations.
Earnings growth and sector valuation
Assume the sector's market cap stays at ₹6,00,000 crore while its profit rises from ₹30,000 crore to ₹40,000 crore.
New P/E = 6,00,000 ÷ 40,000 = 15×
Earnings growth reduces the P/E at an unchanged market value. A sector that looks expensive today may look reasonable after a year of strong profit growth, and vice versa if profits fall.
Economic drivers differ by sector
Examples of drivers to investigate, not mechanical predictions:
| Sector | Potential earnings drivers |
|---|---|
| Financial Services | Credit growth, deposit costs, interest margins, asset quality |
| Information Technology | Global technology spending, deal wins, currency movements |
| Automobile & Auto Components | Consumer demand, financing costs, raw-material prices |
| Oil, Gas & Consumable Fuels | Crude prices, refining margins, regulation |
| Metals & Mining | Global commodity prices, input costs, industrial demand |
| Fast Moving Consumer Goods | Volume growth, rural demand, pricing power |
| Healthcare | Product mix, approvals, hospital occupancy or drug pricing |
| Power | Demand, tariffs, fuel costs, regulation |
For example, an RBI repo-rate cut may support borrowing and vehicle demand, but its effect on banks' net interest margins depends on how quickly lending and deposit rates reprice. Avoid presenting any policy change as a certain earnings outcome.
Compare a sector with its own history. Different sectors normally trade at different multiples. A consumer goods sector at 30× and a metals sector at 12× may both be ordinary for their kind of business; the more useful question is how each compares with its own past range and current growth.
Building a sector valuation sheet in Excel
Recommended fields for each Nifty 50 constituent:
- Company name and NSE symbol.
- Official NSE sector and constituent effective date.
- Last price and valuation date.
- Outstanding shares and full market cap.
- Official IWF and free-float market cap.
- Annual attributable PAT, earnings period and reporting basis.
- Company P/E, sector aggregate P/E and sector free-float index weight.
- Data source, verification status and any cross-holding caveat.
Run completeness checks before calculating sector or index totals. Where a company has a loss or missing profit, disclose how it was treated instead of hiding it.
Key takeaways
- Analyse the economy, index, sector and company together.
- Sector aggregate P/E = combined market cap ÷ combined aligned earnings, never a simple average of P/Es.
- Full-cap sector share and free-float index weight are not the same.
- Earnings quality, growth and risks matter as much as the multiple.
- Use dated, sourced figures and the official NSE sector classification.
Worked examples are hypothetical; snapshot figures are derived, historical and indicative.
An account with sector and valuation tools
Study companies within each sector, with financials and valuation data, before investing. Free to open
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Frequently Asked Questions
How do you calculate a sector's P/E?
Add up the full market caps of all companies in the sector and divide by their combined aligned earnings. Do not average the individual P/Es.
Why not take the average of company P/Es?
A simple average gives small-earnings, high-P/E companies too much influence. The aggregate method reflects what the market pays for the sector's combined earnings.
Is a sector's share of market cap its index weight?
No. Index weight uses free-float market cap and official IWF data, so it usually differs from the full-cap share.
What if one company in a sector has no earnings data?
Do not report the sector P/E as complete. Fill the gap with a verified figure or show the P/E as unavailable with an explanation.
How should sector valuations be compared?
Compare each sector with its own historical range and growth prospects, since different kinds of business normally trade at different multiples.
Related Reading
- Explore every sector on the dashboard
- What counts as a sector
- Official index weight explained
- Using aligned, attributable profit
- How sector multiples expand and contract
- Valuing individual banks
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