What Is a Good P/E Ratio? Real Benchmarks by Sector, Growth and Interest Rates

Ask ten investors what a good P/E ratio is and you will hear ten versions of the same evasive answer: it depends. That is true, and it is also useless when you are looking at a stock right now and need to decide whether 22 times earnings is a bargain or a warning. So this article does the unpopular thing and gives you actual numbers first. Then it explains when those numbers stop applying, because that is where most of the money is lost.

If you need a refresher on what the ratio measures and how it is calculated, read the complete P/E ratio guide first. This page assumes you know that P/E is simply the share price divided by earnings per share, and focuses on one question only: what number counts as good.

The Short Answer: Benchmark Ranges for the P/E Ratio

The long-run average P/E of the S&P 500 sits around 16 to 17 on trailing earnings. Since the 2010s it has spent most of its time higher, between 20 and 25, because interest rates were low for a long stretch and the index became dominated by fast-growing technology companies. Those two numbers are the anchor for everything below.

Those bands are a starting point, not a verdict. A P/E of 12 is not automatically good and a P/E of 35 is not automatically bad. The rest of this guide is about the three things that move the goalposts: the sector the company is in, how fast its earnings are growing, and what a risk-free alternative pays.

A Good P/E Ratio Depends on the Sector

This is the mistake beginners make most often. They see a utility at 20 times earnings and a software company at 20 times earnings and treat them as equally priced. They are not. Utilities grow slowly, carry heavy debt and are regulated, so the market rarely pays more than the mid-teens for their profits. Software companies grow fast with almost no capital, so 30 times earnings can be a perfectly ordinary price. The utility at 20 is expensive for its sector. The software company at 20 is cheap for its sector.

Rough sector averages look like this. Technology around 28 to 30, with a normal range of 25 to 40. Healthcare and consumer cyclicals in the low twenties. Utilities in the mid-teens. Financials around 14, and energy in the low teens with a range of roughly 8 to 16. A good P/E for a bank is therefore below about 12. A good P/E for a technology company might be anything under 25, provided the growth is real.

Fair Price Index applies exactly this logic in its relative valuation model: every stock is compared with the peers in its own sector, never with the market as a whole. You can see the sector context for any company on its stock page, and browse whole sectors on the stock list.

The Three-Benchmark Test

There is a simple way to turn the vague it-depends into a decision. Compare the current P/E with three reference points. If the stock passes all three it deserves a closer look. If it fails all three, you need a very good reason to buy it anyway.

Notice that none of the three checks uses a fixed number. That is the point. A good P/E is a relative judgment, and the three benchmarks give it something to be relative to.

Interest Rates Change What Counts as Good

Flip the P/E upside down and you get the earnings yield: how much profit you buy for each dollar of share price. A P/E of 20 is an earnings yield of 5 percent. A P/E of 25 is 4 percent. Now compare that with what a 10-year government bond pays. If the bond yields 4.5 percent, a stock with an earnings yield of 4 percent is offering you less than a risk-free investment, and it only makes sense if the earnings will grow. If the bond yields 1 percent, that same stock looks generous.

This is why a P/E of 25 was unremarkable when bonds paid almost nothing and looks demanding when bonds pay 4 or 5 percent. When rates rise, the whole scale of good and bad shifts downward. Any P/E benchmark you read, including the bands above, silently assumes a particular level of interest rates.

Growth Changes It Too: The PEG Ratio

A P/E of 30 on a company growing earnings 5 percent a year is expensive. A P/E of 30 on a company growing 30 percent a year is arguably cheap, because in three years the same share price will represent a much smaller multiple of the larger profits. The PEG ratio captures this by dividing the P/E by the expected annual earnings growth rate.

The classic rule from Peter Lynch says a PEG around 1 is fair, below 1 is attractive and above 2 is expensive. It is a rough tool, because the growth estimate is a forecast and forecasts are often wrong, but it explains why a high P/E can still be a good P/E. The full mechanics are in our PEG ratio guide, and you can test any combination in the PEG calculator.

When a Low P/E Is a Trap

A cheap-looking P/E is the most common way retail investors get hurt, because a low number feels safe. Four situations produce a low P/E that is not good at all.

The first is a cyclical peak. Oil producers, automakers, chipmakers and shipping companies earn enormous profits at the top of their cycle, which compresses the P/E to single digits exactly when earnings are about to collapse. For cyclical businesses a low P/E often signals the top, not the bottom. The second is a one-off gain: a company sells a division or wins a lawsuit, earnings spike for a single year, and the trailing P/E looks absurdly cheap on profits that will never repeat.

The third is debt. P/E ignores the balance sheet completely, so a heavily indebted company can look cheap on earnings while being expensive on enterprise value. Cross-check with EV/EBITDA whenever leverage is significant. The fourth is a business in structural decline, where earnings are falling faster than the share price. The P/E looks low every single year on the way down. Our guide to telling overvalued from undervalued stocks covers how to separate a bargain from a value trap.

When a High P/E Is Fine

The reverse is also true. Some of the best long-term investments of the past decades traded at P/E ratios that looked frightening the entire time. A high P/E is justified when the company converts nearly all of its earnings into free cash flow, reinvests at very high returns on capital, and has a durable advantage that keeps competitors from eroding its margins. Those companies rarely go on sale, and waiting for a P/E of 15 means waiting forever.

The test is not the level of the P/E but whether the growth and the quality behind it are real. Metrics like ROIC and free cash flow answer that question far better than the multiple alone.

Trailing or Forward: Which P/E Should You Judge?

Most quoted P/E ratios are trailing, based on the past twelve months of reported earnings. Forward P/E uses analyst estimates for the next twelve months. Use both. A forward P/E well below the trailing one means analysts expect earnings to grow, which supports a higher current multiple. A forward P/E above the trailing one means they expect earnings to shrink, and the cheap trailing number is misleading. When the two disagree sharply, the story behind the gap matters more than either number.

What the P/E Looks Like on Real Stocks Today

Theory is easier to absorb with live numbers. The panel below pulls the current price and fair value for a few widely held companies straight from Fair Price Index. Compare where each one trades against its fair value, then open the stock page to see its P/E next to the sector average.

Alphabet is the classic case of a dominant company trading below its sector's average P/E, which is why value-minded investors keep returning to it. Tesla is the opposite: a triple-digit P/E that only makes sense if you believe the company's future has little to do with selling cars. Neither number is good or bad on its own. See the full breakdown on the Alphabet and Tesla stock pages.

A Practical Checklist

When you are staring at a P/E and need a decision, run through this in order. Is the number positive and based on normal, repeatable earnings? Is it below the sector average? Is it below the company's own five-year average? Does the earnings yield beat a government bond by a comfortable margin? Is the PEG under about 1.5? Is the debt low enough that P/E is not hiding a leverage problem? Five or six yes answers and you have a genuinely good P/E ratio. Two or three and you have a number that needs a story to justify it.

You do not have to do this by hand. Every stock page on Fair Price Index shows the P/E next to its sector average and blends it into a full fair value estimate with DCF and analyst consensus. Start with the list of most undervalued stocks, or run your own numbers in the free P/E ratio calculator.