What is a PEG Ratio Screen?

A PEG ratio screen is a filter inside a stock screener that finds shares trading at a fair price for their expected earnings growth. It sits among the sharpest filters inside the best stock screener in India, because it merges value and growth into a single, defensible number.

Most beginners start with a plain P/E filter and end up confused. A 35x P/E sounds expensive until you learn that profits are compounding at 35 percent a year. A 9x P/E sounds cheap until you learn that profits are shrinking 20 percent a year. The PEG screen corrects both mistakes in one shot.

What the PEG Ratio Actually Measures

PEG stands for Price/Earnings to Growth. You divide the P/E ratio by the company's earnings growth rate, expressed in percent.

• A PEG below 1.0 suggests the price is low relative to the growth rate.
• A PEG near 1.0 suggests price and growth are aligned.
• A PEG above 1.5 suggests you are paying a premium for that growth.

That single number replaces two separate filters and removes most of the false signals you get from either filter alone.

How the PEG Filter Works in a Stock Screener

Inside any modern Indian screener, you set two values:

• A maximum PEG ratio, usually 1.0 or 1.5
• A minimum growth rate, usually 10 percent or 15 percent so tiny growth numbers do not distort the ratio

The screener then scans every listed company on the National Stock Exchange and the Bombay Stock Exchange, and returns only the names that meet both rules. Some screeners let you choose historical growth (last 3 or 5 years of earnings) or forward growth (analyst forecasts for the next year).

Setting the Right Growth and PEG Cutoffs

There is no single correct threshold. Your cutoffs depend on the investing style you want to follow.

• Strict value: PEG below 0.7 with growth above 8 percent
• Balanced: PEG below 1.0 with growth above 12 percent
• Growth at a reasonable price: PEG below 1.5 with growth above 18 percent

Lower PEG screens catch more bargains and more value traps. Higher PEG screens accept richer prices but rarely miss long-term compounders. Run the same screen with two different thresholds, side by side, and you will quickly see which fits your temperament.

Where a PEG Screen Can Mislead You

The screen is only as honest as the inputs feeding it. Three traps show up again and again.

• One-off earnings. A property sale or a one-time tax credit pushes profit up, drops the P/E, and pulls the PEG below 1.0 for no real reason.
• Forecast errors. Forward PEG uses analyst estimates, and analysts are wrong more often than they admit.
• Cyclical peaks. Steel, cement, sugar, and chemical companies look cheap on PEG near the top of their cycle. Earnings reverse within a year.

Combine the PEG filter with a debt-to-equity check, a return-on-equity check, and a five-year earnings trend. Those three add-ons knock out most of the false positives.

Building a Monthly PEG Screening Routine

Run the same screen on the first weekend of every month. Sort the output by lowest PEG. Then open each result and ask three short questions:

• Is the earnings growth genuine, or is it lifted by accounting tricks?
• Is the balance sheet clean enough to survive a weak year?
• Is the industry in a structural uptrend, or is the growth a temporary bounce?

You will usually end up with a short list of five to ten names. From there, study management quality and competitive position before you buy. The screen never picks a stock for you. It hands you a starting line that is mathematically defensible.

An Example PEG Calculation

Say a mid-cap consumer company trades at 24x earnings. Its profits have grown 20 percent a year for the last five years and analysts expect another 18 percent next year.

• Historical PEG: 24 divided by 20 equals 1.20
• Forward PEG: 24 divided by 18 equals 1.33

Both numbers sit above 1.0 but well below 1.5. A balanced screen passes this stock. A strict value screen skips it. A growth-focused screen happily adds it to the watchlist. Same stock, three valid answers, depending on the rule you started with. That is why writing down your own thresholds before you run the screen matters more than copying someone else's setup.

PEG Screen vs Plain P/E Screen

A plain P/E filter rejects every fast-growing business and rewards every cheap-looking one. The PEG screen fixes that bias. You stop dismissing a 40x P/E company that is doubling profits every two years. You stop chasing an 8x P/E business with collapsing demand and rising debt. That single correction is why serious Indian investors keep the PEG filter near the top of their watchlist.

Frequently Asked Questions

What is a good PEG ratio? A PEG below 1.0 is usually attractive. Anything below 0.5 deserves a second look because the cheapness may be a warning, not an opportunity.

Is PEG better than P/E? Yes, for any company with real earnings growth. PEG normalises P/E by growth, so it compares businesses on a fairer scale.

Can the PEG ratio be negative? Yes. If earnings are shrinking, the growth rate is negative and so is the PEG. Most screens hide these names by default.