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P/E Ratio Calculator

Calculate a stock's price-to-earnings ratio to gauge how expensive it is relative to its earnings.

Result

P/E Ratio
25
Earnings Yield
4%

A lower P/E can mean a stock is undervalued - or that the market expects slower growth. Compare P/E within the same industry rather than across unrelated sectors.

About the P/E Ratio

Is a stock trading at $150 expensive or cheap? The price alone can't answer that, but the price relative to how much the company actually earns per share can start to. The P/E ratio is one of the most widely quoted valuation metrics for exactly that reason.

How It Works

The calculator divides the share price by earnings per share (EPS) to produce the P/E ratio. It also calculates the earnings yield, which is EPS divided by share price, expressed as a percentage, essentially the inverse of the P/E ratio.

P/E ratio = share price / earnings per share (EPS) Earnings yield = (EPS / share price) x 100

Examples

Moderate valuation

A $150 share price with $6.00 in EPS gives a P/E ratio of 25, meaning investors are paying $25 for every $1 of annual earnings, and an earnings yield of 4%.

Higher-growth valuation

The same $150 share price with only $3.00 in EPS doubles the P/E ratio to 50, typically signaling the market expects much faster earnings growth ahead to justify the price.

Advantages

  • Calculates both the P/E ratio and its inverse, earnings yield, in one step
  • Quick way to sanity-check a valuation before digging into a full analysis
  • Highlights that P/E comparisons only make sense within the same industry

Common Mistakes

  • Comparing P/E ratios across unrelated industries as if they mean the same thing
  • Treating a low P/E as automatically "cheap" without checking why earnings expectations are low
  • Mixing up trailing P/E (based on past earnings) with forward P/E (based on projected earnings)

Edge Cases to Watch For

  • If EPS is zero or negative (the company is losing money), the P/E ratio isn't meaningful and the calculator won't return a number.
  • Comparing P/E across industries can be misleading, since capital-intensive or slow-growth sectors like utilities typically trade at much lower P/E ratios than high-growth sectors like technology.
  • A P/E based on trailing twelve-month earnings can look very different from one based on forward (estimated future) earnings, so check which basis a quoted P/E is using.

Common Use Cases

  • Getting a quick read on whether a stock's price looks high or low relative to its earnings
  • Comparing a stock's P/E against its industry average or historical range
  • Converting a P/E ratio into an earnings yield to compare against bond yields
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

What's considered a "normal" P/E ratio?

The long-run historical average for the S&P 500 is roughly 15-20, but this varies enormously by sector - high-growth tech stocks often trade at 30-50+ while mature utilities or banks may trade closer to 10-12.

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Conclusion

The P/E ratio is a starting point for valuation, not a verdict on its own. The long-run S&P 500 average sits around 15 to 20, but a stock trading well above or below that isn't automatically overpriced or a bargain until you understand what growth or risk the market is actually pricing in.

References