PE Ratio Explained: How to Use Price-to-Earnings After Q2 Results

PE ratio explained in a sentence: the price-to-earnings (PE) ratio tells you how many rupees the market is paying right now for each rupee of a company’s earnings per share. No valuation number gets quoted more often in Indian markets. It also jumps around in results season, because the “E” gets refreshed every quarter. In this guide we go through the formula, trailing versus forward PE, what a high or low multiple really tells you, where the ratio misleads, and how to work it out yourself the moment a Q2 result comes out. We use a real BSE filing and the latest Nifty 50 reading published by NSE to do it.

PE ratio explained: the formula and what it measures

The formula itself is short: PE ratio = market price per share ÷ earnings per share (EPS). Investopedia’s PE ratio guide describes it as a measure of a company’s share price relative to its EPS, and adds that people often call it the “price multiple” or “earnings multiple”. Say a stock trades at ₹500 and the company earned ₹25 per share over the past year. The PE is 20. Another way to see it: at today’s price, you’re paying for 20 years of current earnings, assuming those earnings never grow.

Since the ratio is a multiple and not a rupee amount, you can put a ₹100 stock and a ₹10,000 stock side by side and compare them fairly. That’s why it sits on every broker app, every screener and every results-day news story. The catch is that the number is only as good as the EPS underneath it. Before you use any PE, find out which EPS went into it. If you’d like a quick refresher on how EPS is built, including how basic and diluted EPS differ, our guide on EPS meaning in share market covers it.

Trailing PE vs forward PE

You’ll mostly see two versions, and each one answers a different question.

• Trailing PE (TTM PE) takes the current price and divides it by total EPS for the previous 12 months. Investopedia calls this the most popular version, since it rests on reported numbers and not estimates. The weakness is that it looks backward. The price changes every minute of the trading day, while EPS updates just once a quarter.
• Forward PE divides today’s price by expected earnings, using company guidance or analyst estimates for the year ahead. It tries to price the future, and so it can only be as good as the forecast it leans on.

Investopedia also mentions a less common hybrid, built on the last two reported quarters plus estimates for the next two. In India, most screeners and exchange pages show a trailing figure. When a news report says a stock “trades at 30 times earnings” and doesn’t say which earnings, it’s usually trailing. Still, check.

What a high or low PE actually tells you

A high PE means investors are paying a lot for every rupee of today’s profit. Investopedia says that can mean one of two things: the stock is overvalued, or the market expects earnings to grow strongly. A low PE can point to an undervalued stock, or to a market that doubts the earnings will hold up. The ratio on its own can’t tell you which version is true. All it shows is how much optimism is already in the price.

A PE ratio is not a verdict on a company. It is a measure of expectations, and the real question after every quarterly result is whether the numbers just reported justify the expectations already built into the price.

This is why the PE works best as a comparison tool, and Investopedia says much the same: it’s most useful when you compare similar companies in one industry, or a company against its own past. Putting a private bank’s PE next to a software exporter’s or a cement maker’s tells you very little. Their growth rates, capital needs and earnings stability have almost nothing in common.

Earnings yield: the PE turned upside down

Turn the ratio over and you get the earnings yield, which is EPS ÷ price, shown as a percentage. A PE of 20 is the same as an earnings yield of 5%. Investopedia points out that earnings yield comes in handy when earnings are zero or negative, because you can still compare a negative yield, while a PE stops making sense. It also says earnings yield is useful if what you care about is the rate of return on your money, since it shows the current profit base as a percentage of the price you pay.

PEG ratio: adding growth to the picture

The PEG ratio takes the PE and divides it by the earnings growth rate. As Investopedia explains, a PEG below one is usually read as a price that’s low compared with expected growth, and a PEG above one as a price that’s high compared with that growth. For growth stocks it’s a handy filter. But it carries every flaw of whatever growth estimate you feed into it.

India context: what the Nifty 50 PE says right now

The National Stock Exchange publishes a PE for each of its indices. Its price earnings ratio explainer defines index PE as index market capitalisation divided by gross earnings. Those earnings are the profits and losses each constituent reported over the trailing four quarters, taken from consolidated financials and adjusted for free float and capping. NSE falls back on standalone financials only when consolidated ones aren’t available.

NSE index data compiled by Integrato shows the Nifty 50 closing on 12 October 2026 at a PE of 19.12, with a price-to-book ratio of 2.75 and a dividend yield of 1.53%. The same page gives the median Nifty 50 PE since 2015 as 23.1. Monthly snapshots on IndexScreener show 19.36 on 30 September 2026 and 22.75 on 31 December 2025. Put in earnings-yield terms, a PE of 19.12 comes to about 5.23%.

Multiples vary a lot across the market. For the same 12 October 2026 close, the Integrato table lists these index PEs:

The distance between the large-cap Nifty 50 and the Smallcap 250 is a useful reminder that there’s no single “market PE”. A midcap at 28 times earnings isn’t automatically expensive just because the Nifty 50 sits near 19. Judge it against its own segment and its own growth.

Watch the 2021 methodology change

Long-term Nifty PE charts hide a trap. A DSP Insights note dated 24 February 2021, quoting an NSE Indices press release, explained that index earnings would move from rolling four-quarter standalone earnings to rolling four-quarter consolidated earnings from 31 March 2021. Consolidated profits include subsidiaries. So for most index companies the denominator went up, and the published PE came down even though prices hadn’t moved. The year-end 2020 Nifty 50 PE of 38.45 in the Integrato table was calculated the old standalone way, which means you can’t compare it directly with today’s 19.12. Whenever you line up a current PE against history, make sure both readings use the same earnings basis.

How to use the PE ratio after Q2 results

Results season is when PE ratios shift without much fuss. A stock’s price can sit still while its trailing PE rises or falls, just because a new quarter has replaced an old one in the 12-month EPS. Here’s a simple routine we’d follow for the September quarter.

1. Rebuild the trailing EPS. Start with the last full-year EPS, take away the EPS for the same period last year, and add the EPS for the period just reported. For a Q2 result that works out to: FY EPS − H1 EPS of the previous year + H1 EPS of the current year.
2. Use the right EPS line. Go with diluted EPS, and keep the basis (standalone or consolidated) the same as whatever your screener or peer comparison uses.
3. Divide by the latest close. Take the price after the result came out, not an old quote.
4. Check what moved the EPS. Look at other income, exceptional items and tax before you trust the change. Our checklist on quarterly result analysis lists the seven lines worth reading first.
5. Compare like with like. Set the new PE against the company’s own history and its closest listed peers, not the Nifty 50.

Worked example: ICICI Prudential AMC’s Q2 FY27 filing

ICICI Prudential Asset Management Company filed results for the quarter and half year ended 30 September 2026 on BSE. Its results statement (face value ₹1 per share) gives these diluted EPS figures:

Trailing 12-month EPS = 67.03 − 32.81 + 37.50 = ₹71.72. ET Markets reported that the stock closed Monday’s (12 October 2026) session at ₹2,967.40 on BSE. Divide one by the other (2,967.40 ÷ 71.72) and the trailing PE comes to about 41.4.

Now watch what happens at the same price when you pick a different denominator:

• Use only the FY26 EPS of ₹67.03 and the PE is about 44.3. It’s higher because it leaves out the growth in H1 FY27.
• Annualise the latest quarter (17.98 × 4 = ₹71.92) and you get about 41.3. Close enough here, but that shortcut can go badly wrong for seasonal businesses, or after a quarter with unusual income.

The same filing also shows why it pays to look under the EPS. Profit for the quarter was ₹8,889.6 million, compared with ₹9,646.3 million in Q1 FY27 and ₹8,379.9 million in Q2 FY26 (all in rupees million, as reported). Other income was ₹169.1 million in the September quarter, against ₹1,808.0 million in the June quarter. So much of the sequential EPS dip came from a line that isn’t core fund-management revenue. Someone reading only the EPS, and so only the PE, would miss that completely.

Recompute the PE yourself on results day. The headline multiple on an app may still carry last quarter’s earnings, and the gap between the two numbers is often where the real story of the quarter sits.

Limitations of the PE ratio

The PE is useful because it’s simple. That same simplicity is where it falls apart.

• Losses make it meaningless. Investopedia notes that companies with no earnings, or with losses, don’t have a meaningful PE, and it’s usually shown as N/A. Newly listed companies that haven’t yet reported a full set of numbers can show N/A too.
• One-offs distort the denominator. A one-time gain from an asset sale, a tax write-back or a big swing in treasury income can puff up EPS and make the PE look cheap. An exceptional loss does the opposite.
• Growth doesn’t show up. Two companies on the same PE can be very different bets if one grows earnings at 25% and the other at 5%. That’s the gap the PEG ratio tries to fill.
• Cyclical traps. Commodity, metal and auto companies often look cheapest on PE right at the peak of their earnings cycle and dearest at the bottom. That’s the reverse of what a value buyer wants.
• Accounting basis. Standalone and consolidated EPS can be far apart for groups with big subsidiaries, and the 2021 Nifty methodology change shows the same thing at index level.
• Balance-sheet blind spot. The PE ignores debt. A heavily borrowed company and a cash-rich rival can trade on similar multiples and carry very different risk. Look at net debt and ratios such as EV/EBITDA next to it.

A quick checklist before you quote a PE

• Is it trailing or forward, and which 12 months does the EPS cover?
• Is the EPS basic or diluted, standalone or consolidated?
• Does it include the latest quarterly result?
• Did other income or an exceptional item move EPS in a big way?
• Are you comparing it with the right peer group and the company’s own history?
• Is earnings growth strong enough to justify the multiple?

Used like this, the PE is where your questions start, not a shortcut to a buy or sell call. For the full way we read results, from revenue and margins to cash flow and guidance, see our pillar guide on how to analyse quarterly results of a company. And to see how the market is taking the latest Q2 numbers, check the Stock Market Today India hub.

Disclaimer: This article is for information and education only and is not investment advice or a recommendation to buy or sell any security. Please consult a SEBI-registered advisor before making investment decisions.