Profitability and efficiency ratios

P/E — price to earnings (P/L)

4 min

The price-to-earnings ratio — P/E, or P/L (preco / lucro) in Brazil — is the most quoted valuation multiple. It tells you how much you pay for each unit of annual profit.

The formula

P/E = Share price / Earnings per share (EPS)

equivalently:

P/E = Market capitalization / Net income

A worked example

A share trades at 30.00 and earned EPS of 1.50 last year:

P/E = 30.00 / 1.50 = 20

You are paying 20 times annual earnings. A rough intuition: at a constant profit, it would take 20 years of earnings to recoup the price. A lower P/E generally means a cheaper stock relative to its profits — but only generally.

What it tells you

  • A high P/E signals the market expects strong future growth (or the stock is overpriced).
  • A low P/E signals modest expectations (or a bargain the market has missed).

Its limits

  • Earnings are manipulable — one-off gains or write-offs distort the bottom line, so a single year's P/E can mislead.
  • No context alone. A P/E of 20 is cheap for a fast grower and expensive for a stagnant utility. Always compare within the same sector.
  • Useless when profit is zero or negative — the ratio breaks down for loss-making or early-stage companies.

P/E is the right place to start and the wrong place to stop.

Finished reading?
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Risk disclaimer

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