Investors often use valuation ratios to understand whether a stock appears reasonably priced relative to its earnings potential. While the price-to-earnings (P/E) ratio is one of the most widely used measures, the PEG ratio provides a broader perspective on whether a stock’s price appears aligned with its growth potential.
Understanding how to calculate and interpret the PEG ratio may help investors compare companies more effectively, especially in growth-oriented sectors.
PEG ratio formula
Before understanding the PEG ratio, it helps to know the P/E ratio. P/E ratio shows how much investors are willing to pay for a company’s earnings. In simple terms, it compares a company’s share price with the profit it earns per share.
The PEG ratio builds on this by also considering the company’s expected future growth. So, instead of only asking whether a stock looks expensive or cheap today, the PEG ratio also asks whether the company’s expected growth may justify that price.
PEG ratio = P/E ratio ÷ earnings growth rate
For example, if a stock has a P/E ratio of 20 and expected earnings growth of 10%, the PEG ratio becomes 2. In common market practice, the growth rate is usually entered as a whole number rather than as a decimal.
The figures shown are for illustrative purpose only
How to calculate PEG ratio — step-by-step
Here is a simple step-by-step method to calculate the PEG ratio.
Step 1: Find the stock price.
Use the current market price per share. This is used while calculating the P/E ratio.
Step 2: Find earnings per share (EPS).
EPS represents the company’s earnings attributable to each share. The P/E ratio is calculated by dividing the market price per share by EPS.
Step 3: Calculate the P/E ratio.
If the share price is ₹200 and the EPS is ₹10, the P/E ratio becomes 20.
Step 4: Identify the expected earnings growth rate.
The PEG ratio uses expected earnings growth, often projected for the next few years, to evaluate whether the valuation is aligned with expected growth potential.
Step 5: Divide P/E by growth rate.
If the P/E ratio is 20 and the expected growth rate is 10, the PEG ratio becomes 2.
This step-by-step method may help investors understand and apply the PEG ratio formula more easily.
Example of PEG ratio calculation
Suppose a company trades at ₹300 per share and its earnings per share is ₹15. The P/E ratio becomes 20. If expected earnings growth is estimated at 25%, the PEG ratio becomes 0.8 using the formula:
20 ÷ 25 = 0.8
This may suggest that the valuation appears relatively lower when expected earnings growth is considered alongside the P/E ratio.
The figures shown are for illustrative purpose only
How to interpret PEG ratio
PEG ratio interpretation is often discussed around the reference point of 1. A PEG ratio around 1 is commonly interpreted as indicating that valuation and expected growth appear broadly aligned. A PEG ratio below 1 may suggest the stock is trading at a relatively lower valuation compared to expected growth, while a PEG ratio above 1 may indicate that valuation is relatively higher compared to projected earnings growth.
However, the PEG ratio should not be viewed in isolation. Earnings forecasts may change due to business conditions, market movements or sector-specific developments. As a result, investors often evaluate PEG ratios alongside cash-flow trends, leverage, return ratios and broader business fundamentals.
What is a good PEG ratio?
A commonly used broad market interpretation is that a PEG ratio near 1 appears relatively balanced. A PEG ratio below 1 may indicate relatively lower valuation compared to expected growth, while a PEG ratio above 1 may indicate relatively higher valuation relative to growth expectations.
However, there is no fixed benchmark that applies uniformly across all businesses and sectors. Companies with volatile earnings, lower earnings visibility or uncertain growth forecasts may not be evaluated accurately using PEG ratios alone. For this reason, PEG ratios are often used more effectively as comparative tools rather than as standalone conclusions.
PEG ratio vs P/E ratio — A quick comparison
The P/E ratio indicates how much investors are paying for each rupee of current earnings. The PEG ratio adjusts the P/E ratio by incorporating expected earnings growth.
In this sense, the P/E ratio provides a valuation snapshot based on current earnings, while the PEG ratio attempts to place that valuation within a future growth context.
This distinction becomes important because two companies may have similar P/E ratios but very different earnings growth expectations. P/E ratios alone may provide limited insight into future growth potential, which is why investors often use PEG ratios when comparing growth-oriented businesses.
FAQs
What is the PEG ratio formula?
The PEG ratio formula is: PEG ratio = P/E ratio ÷ expected earnings growth rate
It combines valuation with expected future earnings growth.
What does a PEG ratio of 1 mean?
A PEG ratio of 1 is commonly interpreted as a level where valuation and expected earnings growth appear broadly balanced.
Is a lower PEG ratio always better?
Not necessarily. A lower PEG ratio may appear favourable in some cases, but business risks, weak earnings quality or uncertain growth forecasts may affect interpretation.
Can PEG ratio be negative?
Yes. A PEG ratio may become negative if earnings growth is negative or if the underlying earnings inputs distort the calculation mathematically, which may reduce the usefulness of the ratio.
Which growth rate should I use for PEG ratio?
PEG ratio calculations commonly use expected earnings growth projections for the next few years.
Is PEG ratio useful for mutual fund analysis in India?
PEG ratio is primarily a stock valuation measure. Mutual fund analysis in India generally focuses more on factors such as portfolio construction, risk measures, expense ratios, asset allocation and scheme-related documents.
How is PEG ratio different from P/E ratio?
The P/E ratio compares price with current earnings, while the PEG ratio adjusts valuation by incorporating expected earnings growth.
What are the limitations of using PEG ratio?
The main limitations include dependence on earnings forecasts, lower usefulness for businesses with unstable earnings, and the fact that PEG ratios do not directly account for debt, cash flows or business quality.
