Price-to-Earnings Ratio Calculator
Enter a stock price and earnings per share to get the P/E ratio, earnings yield, and whether the valuation looks cheap or expensive relative to historical benchmarks. Switch between trailing (actual) and forward (estimated) earnings, add a growth rate for the PEG ratio, or enter a target P/E to find the implied stock price. Results update as you type.
What is the P/E ratio and why does it matter?
The price-to-earnings ratio (P/E ratio) is the most widely used equity valuation metric in finance. It tells you how many dollars investors are willing to pay today for every one dollar of annual earnings the company produces. A P/E of 20x means the market is paying $20 for each $1 of earnings, or equivalently, that the earnings yield (the inverse) is 5%. Because it compresses complex financial data into a single comparable number, the P/E ratio is a quick screen for whether a stock looks cheap or expensive relative to peers, the broader market, or its own history. It is not a buy or sell signal on its own but it is nearly always the first multiple analysts reach for.
Trailing P/E versus forward P/E
Trailing P/E (also called LTM or TTM P/E) uses the sum of the last four quarters of reported earnings per share. Because it is based on audited results it is reliable but backward-looking. Forward P/E uses the consensus analyst estimate for the next twelve months of earnings. Forward P/E is more forward-looking but depends on the accuracy of forecasts, which can miss badly during economic disruptions. By convention, when analysts talk about a stock trading at a certain multiple without qualification, they usually mean forward P/E. When comparing across sources always confirm which earnings figure is being used.
The PEG ratio: growth-adjusting the P/E
A high P/E ratio does not automatically mean a stock is expensive if earnings are growing quickly. The PEG ratio divides the P/E by the annual EPS growth rate to produce a growth-adjusted multiple. Peter Lynch popularised a rule of thumb that a PEG below 1.0 may signal an attractively priced growth stock, while a PEG above 2.0 suggests the price may have run ahead of fundamentals. Like all shortcuts, the PEG ratio has limitations: it uses a single point estimate for growth, ignores capital intensity and balance-sheet risk, and breaks down when earnings are near zero or negative.
Using this calculator for price targets
The implied-price feature works in reverse: rather than dividing price by EPS to get a P/E multiple, it multiplies EPS by a target P/E multiple to produce the price at which the stock would trade if the market re-rated it to that multiple. This is one of the simplest and most common price-target methods used by sell-side analysts. For example, if a company earns $5 EPS and you believe it deserves a 25x multiple based on its growth profile, the implied target price is $125. The upside or downside percentage then tells you how far the current price is from that target.
P/E ratio benchmark ranges
| P/E range | Interpretation | Typical context |
|---|---|---|
| Below 10x | Deep value or distressed | Cyclicals at trough, turnaround candidates, or declining business |
| 10x to 15x | Below historical average | Mature, slow-growth companies; value stocks; high-yield sectors |
| 15x to 20x | Near historical average | Stable large-cap businesses with predictable earnings |
| 20x to 30x | Above average - growth premium | Quality growth companies with a durable competitive moat |
| 30x to 50x | High growth expectations | High-growth tech or biotech; multiple expansion territory |
| Above 50x | Speculative premium | Hyper-growth or early-stage; earnings yield below 2% |
General guidelines used by equity analysts. Actual thresholds vary significantly by sector, growth rate, and interest-rate environment.
Frequently asked questions
What is a good P/E ratio for a stock?
There is no universal answer because a good P/E depends on the sector, growth rate, and interest-rate environment. The long-run average P/E for the S&P 500 is roughly 15 to 16x. A ratio below that range may indicate value, while a ratio well above it implies the market expects above-average earnings growth. Fast-growing technology companies routinely trade at 30 to 50x while utilities and financials often sit below 15x. Always compare to the sector median and to the company's own historical range.
What does a negative P/E ratio mean?
A negative P/E ratio means the company is currently unprofitable - earnings per share is negative. In that case the P/E ratio is mathematically undefined or meaningless for valuation purposes. Analysts switch to other metrics for loss-making companies: EV/Revenue, price-to-sales, or forward P/E based on a future year when profitability is expected.
How is the P/E ratio different from earnings yield?
The earnings yield is simply 1 divided by the P/E ratio, expressed as a percentage. A P/E of 20x corresponds to an earnings yield of 5%. The earnings yield is useful for comparing the return on equities to bond yields: if the 10-year Treasury yields 4.5% and the market earnings yield is 5%, the equity premium is thin. Many value investors prefer earnings yield because it is easier to compare directly with fixed-income returns.
Why is forward P/E usually lower than trailing P/E?
Forward P/E uses estimated future earnings, which analysts typically project to be higher than current earnings (because companies generally grow). Dividing the same price by a larger EPS number produces a smaller ratio. In most market environments, the forward P/E is 10 to 20 percent below the trailing P/E for the same stock. If a company's earnings are expected to fall, the forward P/E can be higher than the trailing P/E.
How do I calculate the implied stock price from a P/E target?
Multiply the earnings per share by the target P/E multiple. For example, if a company earns $8 EPS and you think a 22x multiple is fair, the implied price is $8 times 22, which equals $176. If the stock currently trades at $150, there is approximately 17% upside to your target. This calculator automates that calculation in the implied price and upside fields.
What is the PEG ratio and how should I use it?
The PEG (price/earnings-to-growth) ratio adjusts the P/E for the expected growth rate in earnings. It is calculated as P/E ratio divided by the annual EPS growth rate (expressed as a plain number, not a decimal). A PEG below 1.0 is often considered to indicate potential undervaluation relative to growth prospects, and above 2.0 is sometimes considered overvalued. Use the PEG as one data point among many, not as a standalone decision rule.