What Is PEG Ratio? What Is PEG Ratio in Stocks?
What is PEG ratio? The PEG ratio (price/earnings to growth) divides a stock's P/E ratio by its expected earnings growth rate. It answers: Is the P/E justified by growth? A stock with P/E 40 and 40% growth has PEG 1.0—the P/E matches growth. A stock with P/E 40 and 10% growth has PEG 4.0—potentially expensive.
What is PEG ratio in stocks? In stocks, the PEG ratio is a growth-adjusted valuation metric. It helps compare growth companies: a high P/E can be reasonable if growth is high. The PEG ratio puts P/E in context by dividing it by the earnings growth rate, making it easier to spot growth stocks that may be undervalued or overvalued relative to their growth.
PEG Ratio Formula
The PEG ratio formula is:
PEG = P/E Ratio ÷ Earnings Growth Rate (%)
Use the growth rate as a whole number (e.g., 25 for 25%). Forward P/E and forward growth are often used. Growth rate is typically expected annual earnings growth.
Example: P/E 30, expected growth 20% → PEG = 30 ÷ 20 = 1.5. The stock trades at 1.5 times its growth rate.
How to Calculate PEG Ratio
How to calculate PEG ratio: First, get the P/E ratio (stock price ÷ EPS, or use forward P/E from financial sites). Then get the expected earnings growth rate—analyst consensus, often expressed as a percentage. Divide P/E by the growth rate.
Where to find growth rate
Earnings growth estimates come from analyst consensus (e.g., Reuters, Bloomberg, or company earnings reports). Use 1-year or 5-year expected growth; be consistent when comparing. Historical growth can be used but may not reflect future expectations. Growth rate is critical—small changes significantly affect PEG.
What Is a Good PEG Ratio for Stocks?
What is a good PEG ratio for stocks? General guidelines:
- Below 1.0: Often considered undervalued—P/E is low relative to growth. Favored by growth-at-a-reasonable-price (GARP) investors.
- Around 1.0: Fair value—P/E roughly matches growth.
- Above 2.0: May indicate overvaluation—P/E is high relative to growth.
A "good" PEG depends on the sector and quality. Quality companies with durable growth may justify PEG above 1. Compare to peers. PEG is most useful for growth stocks; for value or no-growth companies, P/E or other metrics may be more relevant.
PEG Ratio vs. P/E Ratio
The P/E ratio shows how much you pay per dollar of earnings. The PEG ratio adds growth: it shows whether that P/E is justified by earnings growth. A stock with P/E 50 might look expensive, but if it's growing 50% per year, PEG = 1.0—arguably fair. A stock with P/E 15 and 5% growth has PEG 3.0—potentially expensive on a growth-adjusted basis. PEG helps level the playing field for growth stocks.
Limitations of the PEG Ratio
The growth rate is an estimate—analyst forecasts can be wrong. PEG works best for companies with positive, predictable growth; avoid using it for negative or volatile growth. Very high growth rates can make PEG misleading (small denominator). Different time horizons (1-year vs 5-year growth) change the result. Use PEG alongside other metrics—P/E, FCF yield, and quality indicators.
PEG Ratio Example
Stock A: P/E 25, growth 25% → PEG = 1.0. Stock B: P/E 25, growth 10% → PEG = 2.5. Stock C: P/E 60, growth 40% → PEG = 1.5. Stock A is fairly valued on a growth basis. Stock B may be expensive. Stock C has a high P/E but the PEG suggests it may be reasonable given growth. Compare all three to sector averages.
Frequently Asked Questions
What is PEG ratio?
The PEG ratio (price/earnings to growth) divides a stock's P/E ratio by its expected earnings growth rate. It adjusts the P/E for growth: PEG = P/E ÷ Growth Rate (as a percentage). A PEG below 1 may suggest the stock is undervalued relative to its growth; above 2 may suggest overvaluation. It helps compare growth stocks with different P/Es by factoring in how fast earnings are expected to grow.
What is PEG ratio in stocks?
PEG ratio in stocks is a valuation metric that compares P/E to earnings growth. It answers: Is the stock's price justified by its growth? A high P/E can be reasonable if growth is high—PEG captures that. Use trailing or forward P/E and expected 1-year or 5-year earnings growth. PEG is popular for growth stock analysis because it adds growth into the valuation picture.
What is the PEG ratio formula?
The PEG ratio formula is: PEG = P/E Ratio ÷ Earnings Growth Rate (%). Example: P/E of 30, growth rate 25% → PEG = 30 ÷ 25 = 1.2. Use the growth rate as a whole number (25, not 0.25). Forward P/E and forward growth are often used. Some analysts use 5-year expected growth. Be consistent when comparing companies.
How do you calculate PEG ratio?
Get the P/E ratio (stock price ÷ EPS). Get the expected earnings growth rate (analyst consensus, often in %). Divide P/E by the growth rate. PEG = P/E ÷ Growth Rate. Example: P/E 40, growth 20% → PEG = 40 ÷ 20 = 2.0. Use forward P/E and forward growth when available. Growth rate can be from analyst estimates or historical earnings growth.
What is a good PEG ratio for stocks?
A good PEG ratio for stocks depends on context. Generally: PEG below 1 is often considered undervalued. PEG of 1 suggests fair value (P/E matches growth). PEG above 2 may indicate overvaluation. Compare to sector peers. Quality companies can justify PEG above 1. Very high growth (>30%) may warrant higher PEG. Use forward growth estimates for relevance.