Learn what the PEG ratio measures, how it combines valuation and growth, and why investors use it beside the P/E ratio.
The price/earnings-to-growth (PEG) ratio compares a stock’s P/E ratio with its expected earnings growth rate.
The goal is to judge valuation in light of growth rather than looking at the P/E ratio alone. A company with a high P/E may still look reasonable if earnings are expected to grow quickly.
A common shortcut is:
PEG ratio = P/E ratio / expected earnings growth rate
If a stock has a P/E of 24 and analysts expect earnings to grow at 12% per year, the PEG ratio is 2.0.
Lower PEG values are often seen as more attractive, but the number depends heavily on the quality of the growth forecast.
Suppose Company B trades at a P/E of 18 and analysts expect earnings growth of 9%.
18 / 9 = 2.0
If Company C trades at a P/E of 25 but expected growth is 25%, its PEG is 1.0. Even though Company C has the higher P/E, its valuation may look more reasonable once growth is considered.
An investor says, “A PEG below 1 guarantees a bargain.”
Answer: No. The PEG ratio depends on estimated growth, and those forecasts can be too optimistic.