PEG Ratio Calculator

What is a PEG Ratio Calculator?

A PEG Ratio Calculator is a free online tool that helps investors calculate the Price-to-Earnings-to-Growth (PEG) ratio of a stock by combining its P/E ratio with its expected earnings growth rate. The result gives you a growth-adjusted valuation metric that tells you whether you are paying a fair price for a stock relative to how fast its earnings are expected to grow.

While the P/E ratio alone shows how expensive a stock is relative to current earnings, the PEG ratio goes a step further by factoring in the company's growth potential. This makes it a significantly more powerful tool for evaluating growth stocks where a high P/E ratio can be misleading without context. The Dhanarthi PEG Ratio Calculator is ideal for retail investors, equity analysts, and anyone looking to go beyond basic valuation metrics in their stock research. Use it alongside the Dhanarthi P/E Ratio Calculator for a complete, two-dimensional view of any stock's valuation.

How Does the PEG Ratio Calculator Work?

The PEG Ratio Calculator works by taking two key inputs: the company's P/E ratio (which you can either enter directly or derive from the stock price and EPS) and the expected annual earnings growth rate of the company, expressed as a percentage.

The calculator then divides the P/E ratio by the earnings growth rate to arrive at the PEG multiple. This single number tells you whether the stock's valuation is in line with, below, or above its growth potential.

The earnings growth rate you enter can be based on historical EPS growth (backward-looking), analyst consensus estimates for the next one to five years (forward-looking), or management guidance provided during quarterly earnings calls. For the most reliable PEG calculation, most investors prefer to use a one-year or five-year forward earnings growth rate, since the whole point of the PEG ratio is to factor in future potential.

The interpretation of the result is straightforward. A PEG below 1 generally suggests the stock may be undervalued relative to its growth. A PEG of exactly 1 indicates the stock is fairly valued. A PEG above 1 suggests the stock may be overvalued relative to its expected growth rate.

PEG Ratio Formula

The PEG Ratio formula is simple and builds directly on the P/E ratio:

PEG Ratio = P/E Ratio / Earnings Growth Rate (%)

Where:

• P/E Ratio = Current Market Price Per Share / Earnings Per Share (EPS)
• Earnings Growth Rate (%) = The expected annual growth rate of the company's EPS, expressed as a percentage (not a decimal). For example, a 15% growth rate is entered as 15, not 0.15.

The expanded full formula is:

PEG Ratio = (Market Price Per Share / EPS) / Annual EPS Growth Rate (%)

Breaking down each variable:

• Market Price Per Share: The current trading price of one share of the company on the NSE or BSE.
• EPS (Earnings Per Share): Net profit after tax divided by the total number of outstanding shares.
• Annual EPS Growth Rate (%): The percentage rate at which the company's earnings per share are expected to grow annually. This can be sourced from analyst reports, company guidance, or historical growth trends.

A critically important point: the earnings growth rate must be entered as a percentage figure (for example, 20 for 20% growth), not as a decimal (0.20). Many investors accidentally enter the growth rate as a decimal and get a PEG ratio that is 100 times larger than the correct value.

Example Calculation

Let us walk through two practical examples to see how the PEG Ratio Calculator works and why it often gives a more useful insight than the P/E ratio alone.

Example 1 - Growth Stock That Looks Expensive on P/E but Fairly Valued on PEG:

Step 1 - Calculate P/E Ratio: P/E = 600 / 20 = 30x At 30x P/E, this stock looks expensive compared to the market average of around 20x.

Step 2 - Calculate PEG Ratio: PEG = 30 / 35 = 0.86 A PEG of 0.86 (below 1) suggests that despite the seemingly high P/E of 30x, the stock is actually undervalued relative to its strong 35% earnings growth rate. The market may be underpricing this growth, making it potentially attractive for a growth-oriented investor.

Example 2 - Slow-Growth Stock That Looks Cheap on P/E but Overvalued on PEG:

Step 1 - Calculate P/E Ratio: P/E = 150 / 15 = 10x At 10x P/E, this stock looks very cheap compared to the broader market.

Step 2 - Calculate PEG Ratio: PEG = 10 / 5 = 2.0 A PEG of 2.0 (well above 1) reveals that despite the low P/E, investors are paying twice what the earnings growth rate justifies. The low P/E is not a bargain here because the company is growing very slowly. This is what is often referred to as a value trap.

These two examples show precisely why the PEG ratio is more informative than the P/E ratio alone.

How to Use Dhanarthi's PEG Ratio Calculator?

• Step 1: Enter the current market price of the stock. Use the live trading price or the most recent closing price from NSE, BSE, or your broker's trading platform.
• Step 2: Enter the Earnings Per Share (EPS) of the company. Use the trailing twelve months (TTM) EPS from the company's latest annual report or the sum of the last four quarterly EPS figures. Alternatively, use the forward EPS estimate if you want to calculate a forward-looking PEG.
• Step 3: The calculator will automatically compute the P/E ratio from these two inputs. Alternatively, if you already know the P/E ratio directly, you can enter it in the P/E field.
• Step 4: Enter the expected annual earnings growth rate as a percentage. For example, if you expect the company's EPS to grow at 20% per year, enter 20. You can source this figure from analyst consensus reports, the company's investor presentations, or by calculating the compound annual growth rate (CAGR) of historical EPS using the Dhanarthi CAGR Calculator.
• Step 5: Click the Calculate button. The PEG Ratio will be displayed instantly.
• Step 6: Interpret the PEG result. A PEG below 1 indicates potential undervaluation. A PEG of 1 signals fair value. A PEG above 1 suggests the stock may be overvalued relative to its growth. Compare the result with sector peers for the most meaningful conclusions.

Benefits of Using This Calculator

• Adds Growth Context to P/E Valuation: The single most important benefit of the PEG Ratio Calculator is that it prevents you from drawing incorrect conclusions from a high or low P/E ratio by adding the critical dimension of earnings growth. A stock with a P/E of 40x is not automatically overvalued if its EPS is growing at 50% per year.
• Helps Identify True Value Stocks and Growth Picks: A PEG below 1 with strong fundamentals can signal a genuinely undervalued opportunity. The PEG Ratio Calculator helps you find these situations quickly, without having to manually divide ratios or build spreadsheets.
• Enables Fair Cross-Stock Comparisons: Unlike raw P/E ratios, the PEG ratio normalises for growth, which means you can more fairly compare two stocks with different P/E ratios and different growth rates on the same scale. This is especially useful when comparing companies in the same sector with varying growth profiles.
• Faster Stock Screening: During periods of high market activity or earnings season, investors need to evaluate multiple stocks quickly. The Dhanarthi PEG Ratio Calculator allows you to compute and compare PEG ratios for several companies in minutes, saving significant research time.
• Supports Both Value and Growth Investing Philosophies: Whether you are a value investor looking for cheap stocks with solid growth or a growth investor ensuring you are not overpaying for a high-growth company, the PEG ratio serves both investment styles effectively.

Who Should Use This PEG Ratio Calculator?

• Growth Stock Investors: Investors who target high-growth companies where P/E ratios are naturally elevated will find the PEG ratio invaluable. It tells them whether the premium valuation is justified by the underlying earnings growth rate or whether they are simply overpaying.
• Value Investors Avoiding Value Traps: Classic value investors who screen for low P/E stocks can use the PEG ratio to filter out value traps where a low P/E reflects low or negative growth rather than genuine undervaluation. A low P/E combined with a high PEG is a classic warning sign.
• Intermediate and Advanced Retail Investors: Investors who have moved beyond basic P/E analysis and want to incorporate a growth dimension into their stock screening will find the PEG Ratio Calculator a natural next step in their fundamental analysis toolkit.
• Equity Research Students and Analysts: Finance students learning fundamental analysis, as well as junior analysts building stock coverage, can use this calculator to practise growth-adjusted valuation and develop intuition for interpreting PEG multiples across different sectors.
• Long-Term Investors Building a Portfolio: Investors building a long-term wealth portfolio benefit from identifying stocks that offer growth at a reasonable price (GARP). The PEG ratio is the cornerstone metric of the GARP investing strategy, famously popularised by legendary investor Peter Lynch.

Where Can You Use This PEG Ratio Calculator?

• During Stock Screening and Research: When building a shortlist of stocks to analyse in depth, use the PEG Ratio Calculator as a quick filter. Stocks with a PEG below 1 and improving earnings momentum can be prioritised for further research.
• When Evaluating High-Growth Sectors: In fast-moving sectors like technology, pharmaceuticals, or consumer discretionary, P/E ratios are often high. The PEG ratio helps you distinguish between stocks that are legitimately valued for their growth and those that are simply overpriced relative to realistic earnings projections.
• During Earnings Season: After quarterly results are announced and EPS figures are updated, recalculate the PEG ratio for stocks in your watchlist using the new EPS and any revised growth guidance from management. This helps you stay on top of valuation changes as the earnings picture evolves.
• Before Investing in an IPO: For a company coming to the primary market, apply the PEG ratio to the IPO price using the company's projected EPS and growth rate. Compare the resulting PEG to listed peers in the same sector to assess whether the IPO price offers good value. Combine this with the Dhanarthi Price-to-Book Ratio Calculator for a more complete IPO valuation.
• When Comparing Portfolio Holdings Against Peers: At regular intervals, run the PEG ratio for each stock in your portfolio and benchmark it against the PEG of the sector average. If a stock's PEG has expanded significantly above its peers, it may be a signal to review your position and consider rebalancing.

Types of PEG Ratios

Understanding the different variants of the PEG ratio helps you use the Dhanarthi PEG Ratio Calculator with greater precision and accuracy.

• Trailing PEG: This version uses the trailing twelve months (TTM) P/E ratio in the numerator and the historical earnings growth rate over the past one, three, or five years in the denominator. Since both inputs are based on actual reported data, the trailing PEG is more objective and reliable. However, it is backward-looking and may not accurately reflect recent changes in a company's growth trajectory.
• Forward PEG: This version uses either the trailing P/E or forward P/E ratio and divides it by the projected future earnings growth rate, typically sourced from analyst consensus estimates or management guidance for the next one to three years. The forward PEG is more relevant for evaluating growth companies where future potential matters more than historical performance. The limitation is that growth estimates can and do change, introducing an element of uncertainty.
• PEGY Ratio (PEG with Dividend Yield): An extension of the standard PEG ratio, the PEGY ratio adds the stock's dividend yield to the earnings growth rate in the denominator. This makes it more appropriate for dividend-paying companies where total shareholder return includes both capital appreciation and dividends. The formula is: PEGY = P/E / (EPS Growth Rate + Dividend Yield %). This variant is more commonly used in mature, income-generating sectors like FMCG, utilities, and established financial services companies.

PEG Ratio vs P/E Ratio: Key Differences

Both the PEG ratio and the P/E ratio are valuation tools, but they serve different purposes and have meaningfully different strengths and limitations. Understanding the distinction helps you choose the right metric for the right situation.

The P/E ratio is purely a measure of current price relative to current earnings. It tells you how much the market is willing to pay for each rupee of earnings today. It is easy to calculate, universally understood, and widely available on any financial platform. However, the P/E ratio completely ignores future earnings growth, which means it tends to make high-growth companies appear overvalued and slow-growth companies appear cheap, when the reality may be the opposite.

The PEG ratio corrects this blind spot by dividing the P/E ratio by the expected earnings growth rate. This normalisation allows you to compare a fast-growing company trading at 35x P/E with a slow-growing company at 12x P/E on a more level playing field. If the fast grower has a PEG of 0.8 and the slow grower has a PEG of 2.4, the fast grower is actually the cheaper stock on a growth-adjusted basis, despite having a much higher headline P/E.

The P/E ratio is the better starting tool for broad market analysis, index comparisons, and initial stock screening. The PEG ratio is more useful for deeper individual stock valuation, particularly for companies with above-average or rapidly changing earnings growth rates. Use both together for the most complete valuation picture, which is why Dhanarthi provides both the Dhanarthi P/E Ratio Calculator and this PEG Ratio Calculator as companion tools.

Common Mistakes to Avoid

• Entering the Growth Rate as a Decimal Instead of a Percentage: This is the single most frequent error when using a PEG calculator. If the expected growth rate is 20%, enter 20, not 0.20. Entering 0.20 will produce a PEG that is 100 times too large, completely distorting the interpretation. Always confirm your growth rate input is expressed as a percentage number.
• Using Inconsistent Time Periods for P/E and Growth Rate: The P/E ratio and the earnings growth rate should ideally be based on the same time horizon. If you use a trailing P/E (based on the last 12 months of EPS), pair it with a recent historical growth rate. If you use a forward P/E (based on next year's estimated EPS), pair it with a forward earnings growth rate estimate for the same period.
• Applying PEG to Loss-Making Companies: The PEG ratio requires positive earnings. If a company has a negative EPS, the P/E ratio is undefined, and the PEG ratio cannot be calculated at all. Similarly, if the projected growth rate is negative (earnings are expected to decline), the PEG formula produces a negative number which is not interpretable. Use alternative valuation metrics like Price-to-Sales in such cases.
• Treating PEG Below 1 as a Guaranteed Buy Signal: A PEG below 1 is a positive signal, but it is not a buy recommendation by itself. A low PEG may result from an overly optimistic growth estimate that is unlikely to be achieved. Always verify the quality and credibility of the growth rate assumption before acting on the PEG result. Cross-check with revenue growth, operating margins, and return on equity before drawing conclusions.
• Ignoring Sector Context: Like the P/E ratio, PEG ratios can vary by sector. Technology and healthcare companies often carry higher P/E multiples and can still have acceptable PEGs if their growth rates are high enough. Capital-intensive, cyclical sectors like metals or construction may have structurally different valuation norms. Always interpret PEG ratios in the context of sector benchmarks, not just the universal PEG = 1 rule.

Tips to Use PEG Ratio Effectively in Stock Research

• Source Growth Estimates From Multiple Inputs: Do not rely on a single source for the earnings growth rate. Cross-check analyst consensus estimates from financial platforms with the company's own guidance from recent quarterly calls and investor presentations. Where possible, use the five-year projected CAGR of EPS rather than a one-year estimate for a more stable PEG reading.
• Use CAGR of Historical EPS as a Sanity Check: Before using a forward growth rate in your PEG calculation, compute the three-year or five-year historical EPS CAGR using the Dhanarthi CAGR Calculator. If the projected growth rate is dramatically higher than the historical growth trend with no clear business catalyst, the forward PEG may be falsely optimistic.
• Combine PEG With Return on Equity and Debt Levels: A low PEG is most meaningful when the company also has a high and stable return on equity and a manageable debt-to-equity ratio. High-growth companies with excessive leverage can show attractive PEG ratios but carry significant financial risk that the ratio does not capture.
• Build a Sector PEG Comparison Table: For any sector you are researching, calculate the PEG ratio of five to ten leading companies and rank them from lowest to highest. This peer comparison quickly highlights which stocks offer the best growth-adjusted value within the sector. Combine this view with the Dhanarthi Price-to-Sales Ratio Calculator for a multi-metric peer ranking.
• Re-evaluate PEG After Earnings Guidance Changes: Corporate earnings guidance can change significantly after quarterly results. If a company revises its growth outlook downward, the denominator of the PEG ratio shrinks, potentially pushing the PEG well above 1 even if the share price has not moved yet. Staying current with guidance changes and recalculating PEG regularly is essential for active investors.

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