PEG Ratio Calculator (P/E ÷ Growth)

FINANCE GARP PEG PETER LYNCH VALUATION
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PEG ratio calculator. Peter Lynch's growth-adjusted P/E. Computes from P/E and expected earnings growth. Lynch threshold verdict (<1 attractive, ~1 fair, >2 expensive) + dividend-yield-adjusted PEGY variant.

RT-FIN-229 · Finance & Money

PEG Ratio Calculator

trailing or forward (use the same)
expected EPS growth (annual)
for PEGY variant
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How to use the PEG ratio calculator

Enter the P/E ratio

Use either trailing (TTM) or forward P/E — be consistent with the growth rate. Most practitioners use forward P/E with forward growth for the cleanest forward-looking comparison. Get P/E from Yahoo Finance, your broker, or compute it directly using our P/E ratio calculator (RT-FIN-228) from share price and EPS.

Enter the earnings growth rate (%)

Expected annual EPS growth, in percent. Sources: (1) Analyst consensus 5-year EPS growth estimate — Yahoo Finance "Analysis" tab, Refinitiv I/B/E/S consensus. (2) Historical CAGR — recent 3-5 year actual EPS CAGR (if trajectory is stable). (3) Your own forecast from a bottoms-up model. Critical: match the time horizon — if using forward P/E (next 12 months), use 1-year forward growth; if using trailing P/E, historical 5y CAGR is reasonable.

(Optional) Enter dividend yield for PEGY variant

For dividend-paying stocks, the standard PEGY (PEG-Yield) variant adds dividend yield to the growth denominator: PEGY = P/E ÷ (growth + dividend yield). Captures total shareholder return rather than just capital appreciation. Useful for comparing growth stocks vs dividend stocks on apples-to-apples basis. Leave at 0 if non-dividend payer or for the classic Lynch PEG.

Read PEG + Lynch verdict

Peter Lynch's heuristic from "One Up On Wall Street" (1989): PEG < 1.0 attractive (growth ahead of price); PEG ~1.0 fairly valued; PEG > 2.0 expensive (paying too much for growth). The visual bar shows where your stock sits on the Lynch spectrum. A green zone (PEG < 1) is buy territory; the red zone (> 2) is avoid territory.

Sanity-check the inputs

PEG breaks down at three edges. (1) Negative earnings — P/E undefined. Use other metrics. (2) Negative growth — PEG mathematically undefined. (3) Very low growth (<1%) — denominator tiny, PEG hypersensitive to estimate noise. Even within the valid range, PEG is sensitive to growth assumption. Run a sensitivity analysis: growth ±2 percentage points reveals how robust the PEG verdict is.

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PEG — Peter Lynch\'s growth-adjusted valuation classic

The PEG ratio (Price/Earnings to Growth) was popularised by Peter Lynch in his 1989 investing classic "One Up On Wall Street". Lynch managed Fidelity\'s Magellan Fund from 1977-1990, generating a 29% annualised return — among the best long-term track records in mutual-fund history. His central insight: P/E in isolation is misleading. A stock with P/E 35 might be cheap if it\'s growing earnings at 50% per year; a stock with P/E 12 might be expensive if it\'s growing at only 2%. PEG divides P/E by growth to make the comparison apples-to-apples. Lynch\'s rule of thumb: "The P/E ratio of any company that\'s fairly priced will equal its growth rate." i.e. PEG ≈ 1.0 = fair. Below 1.0 attractive. Above 2.0 expensive.

Why PEG matters more than raw P/E

Consider two stocks. Stock A: P/E 30, growing earnings at 25% per year → PEG 1.2 (slightly expensive but reasonable for the growth). Stock B: P/E 12, growing at 3% per year → PEG 4.0 (expensive despite low headline P/E). Raw P/E says Stock B is cheap; PEG says Stock A is the better buy. This insight powers the entire "Growth at a Reasonable Price" (GARP) investing style — picking stocks where the growth-adjusted price is attractive. Many of the legendary fund managers (Lynch, Jim Slater of Capel-Cure Myers, John Templeton in his early years) used PEG-style frameworks. Modern factor investing has formalised GARP into systematic quant strategies.

Lynch\'s rule: the P/E of any fairly-priced company equals its growth rate. PEG above 2 = avoid. PEG below 1 = look harder. Half a century of out-of-sample evidence suggests the heuristic still works.

Where PEG breaks down

PEG is a heuristic, not a law. Three failure modes. (1) Volatile / non-linear earnings: a one-time charge in the trailing period inflates P/E and depresses PEG; a one-time gain does the opposite. Use normalised EPS for cyclicals and adjust for special items. (2) Negative or near-zero growth: PEG is undefined (denominator approaches zero). Use other tools — DDM for stable income payers, asset-based valuation for declining firms. (3) Hyper-growth firms: a startup growing 100% per year has PEG ~0.5 even at P/E 50 — but the growth almost certainly won\'t persist at 100%. PEG works best for steady-state growth firms with 5-30% sustainable growth. Outside that range, supplement with other metrics.

ASEAN context — PEG for regional stocks

PEG translates well across markets but requires market-appropriate growth expectations. For ASEAN large-caps: typical sustainable growth is 5-12% (faster than developed markets, slower than India/China). Banks: 5-8%. Telcos: 3-5%. Plantation/agri: highly cyclical, normalise carefully. Tech (Sea, Grab, GoTo, Bukalapak): high-growth, often loss-making — PEG inappropriate, use EV/Sales. Singapore REITs have especially clean PEG calculations because dividend payouts are stable and growth (mostly from acquisitions and rent escalations) is predictable. Many DBS Research / OCBC Research / Macquarie ASEAN reports cite PEG explicitly when comparing across regional names. For cross-market screening (e.g. which Indonesian bank vs which Malaysian bank), PEG provides a defensible apples-to-apples lens.

10 Things to Know About PEG

01

PEG = P/E ÷ earnings growth (%). Peter Lynch\'s growth-adjusted P/E. Popularised in One Up On Wall Street (1989).

02

Lynch heuristic: PEG < 1.0 attractive, ~1.0 fairly valued, > 2.0 expensive. Quoted in every value-investing textbook since.

03

Lynch managed Fidelity Magellan 1977-1990 at 29% annualised return. One of the best long-term track records in mutual fund history.

04

PEGY variant: P/E ÷ (growth + dividend yield). Includes total shareholder return — better for dividend-paying stocks.

05

PEG works because price should reflect future growth. High-growth firms deserve high P/E; low-growth firms must trade at low P/E for fair value.

06

GARP investing (Growth at a Reasonable Price): the entire investing style PEG enables. Used by Lynch, Slater, Templeton, modern quants.

07

PEG breaks down for negative-growth firms and near-zero-growth firms — denominator tiny or negative makes the ratio meaningless.

08

Forward PEG (forward P/E ÷ forward growth) is the rigorous version. Most practitioner reports cite this.

09

Sensitivity matters. A 5-point change in growth assumption can flip PEG verdict from attractive to expensive. Always sensitivity-test.

10

For hyper-growth firms (100%+ growth), PEG is artificially low (~0.5 even at P/E 50). Growth won\'t persist at that rate — supplement with other metrics.

Frequently asked questions

  • Either, but be consistent. Forward PEG = forward P/E ÷ forward growth is the most rigorous variant — what most analyst reports cite. Trailing PEG = trailing P/E ÷ historical growth (typically 5y CAGR) is concrete but backward-looking. Don\'t mix them: trailing P/E ÷ forward growth produces a misleadingly low PEG that overstates attractiveness. For Lynch\'s original heuristic, he typically used trailing P/E with historical 5y growth — but in modern practice, forward PEG dominates.

  • No — it\'s a screening criterion, not a buy signal. PEG < 1 means the stock is attractively priced if the growth is real and sustainable. The two failure modes: (1) Growth estimate is wrong — analysts over-extrapolate from a strong recent quarter, or the firm is at a cyclical peak. (2) Growth is real but risky — emerging-market currency exposure, single-customer concentration, regulatory risk. PEG < 1 is "look harder" — investigate growth quality, business durability, and balance sheet before buying.

  • PEGY = P/E ÷ (growth rate + dividend yield) — adjusts PEG for dividend income. Useful because total shareholder return = capital appreciation + dividends, and PEG only captures the appreciation side. Example: two firms with P/E 15 and 5% growth. Firm A pays 4% dividend yield (PEGY = 15/(5+4) = 1.67). Firm B pays 0% dividend (PEGY = 15/5 = 3.0). Same PEG, very different PEGY — Firm A delivers materially better total return at the same P/E. The PEGY variant matters most for dividend-paying stocks (banks, REITs, utilities, consumer staples) where dividends are a significant fraction of total return.

  • Hyper-growth tech firms often have eye-watering PEG because their P/E is very high AND consensus growth (typically 15-25%) doesn\'t reflect the optionality value embedded in the price (FSD autonomy, energy storage, robotics, AI compute). The market is pricing scenarios analysts can\'t cleanly model. PEG underestimates value for optionality-heavy stocks. For these, DCF with explicit option-value modules or sum-of-the-parts analysis works better than PEG. Apple\'s services pivot in 2017-2020 looked overpriced on PEG but proved correct in hindsight; whether Tesla\'s autonomy bet plays out similarly is the open question.

  • Yes — it\'s a remarkably durable heuristic. Modern factor investing has formalised PEG into "growth value" factors that screen for low P/E + high earnings growth. Quantitative strategies (AQR\'s style premia, Dimensional\'s factor portfolios, BlackRock\'s smart beta) all incorporate growth-adjusted price metrics. PEG remains in every CFA Level 2 reading, every value investing course, every fund management presentation. Academic research confirms PEG-screened portfolios have generated risk-adjusted outperformance vs broad market across multiple decades and geographies. The "GARP" style premia is real.

  • For accurate PEG, normalise EPS to exclude non-recurring items: tax-law-change charges, litigation settlements, asset impairments, one-time gains from divestitures. Sources: management\'s "adjusted EPS" or "operating EPS" line in the 10-Q/10-K, analyst consensus normalised EPS, your own bottom-up adjustment. Caution: don\'t simply use non-GAAP adjusted EPS without checking what\'s being excluded — some firms (especially SaaS) exclude stock-based compensation, which is a real economic cost. The CFA Institute and Damodaran both recommend treating SBC as an expense for valuation purposes.

  • For firms with sustained growth < 2-3% (utilities, mature consumer staples), PEG becomes hypersensitive — small changes in the denominator swing PEG dramatically. Better tools: (1) Dividend Discount Model (RT-FIN-227) — exactly designed for this profile. (2) Earnings yield vs Treasury comparison via Fed Model. (3) EV/EBITDA for direct multiple comparison without explicit growth assumption. For very-low-growth firms, PEG produces extreme verdicts ("avoid! 5.0!") that mislead — the firm may be perfectly investable at low growth if total shareholder yield is high enough.

  • Yes, with regional adjustments. ASEAN large-caps typically have sustainable growth in the 5-12% range — somewhat faster than developed markets, slower than India/China. Banks: 5-8% (lower in low-rate cycles). Telcos: 3-5% (mature, capex-heavy). SG REITs: 3-7% (predictable, ideal for PEG). Plantation/agri: highly cyclical, normalise carefully or use earnings smoothed over a commodity cycle. ASEAN PEG should be compared within ASEAN — using a developed-market PEG threshold (Lynch\'s <1 = attractive) is too strict because emerging-market discount rates are higher.

  • No. P/E, growth rate, dividend yield — every input stays in your browser. The PEG and PEGY calculations + Lynch interpretation all run as client-side JavaScript. Open DevTools → Network when you click Calculate and you\'ll see zero outbound requests. Safe for confidential portfolio screening.

  • Peter Lynch, One Up On Wall Street (1989) — the original PEG popularisation. Lynch\'s sequel Beating the Street (1993) adds case studies. Modern academic treatment: Damodaran A., Investment Valuation, Ch.18. Jim Slater\'s The Zulu Principle (1992) extends GARP to UK small-caps. CFA Institute Level 2 Equity Investments has a full reading on price multiples including PEG. Damodaran\'s data archive (pages.stern.nyu.edu/~adamodar/) has industry-average PEG updated annually.

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Method & sources

How it computes

PEG divides the price/earnings ratio by the expected earnings growth rate in percentage points, on the rule of thumb that a fairly priced company trades at a multiple close to its growth rate. Where a dividend is paid, the dividend-adjusted form (sometimes PEGY) adds the dividend yield to the growth term, on the reasoning that a shareholder is compensated by growth and income together rather than by growth alone.

What this tool implements

  • Non-positive growth returns no ratio and says why. PEG is undefined for a shrinking company — the denominator is the whole point — and a negative PEG looks like a bargain while meaning nothing.
  • Growth below one percentage point produces an explicit warning rather than a number presented plainly: the denominator is then so small that ordinary estimate error swings the ratio wildly.
  • The dividend-adjusted figure is shown only when a dividend yield is actually entered, so a zero-yield company does not display two identical ratios under different names.
  • ⚠️ THE GROWTH HORIZON IS UNDEFINED AND IT CHANGES THE ANSWER. Next year's growth, a three-year estimate and a five-year estimate give three different PEGs for the same company, and the convention does not specify which to use. Compare PEGs only when they were built on the same horizon.
  • ⚠️ This is a heuristic from a practitioner book, not a valuation model. It has no theoretical derivation, it implicitly assumes constant growth, and it systematically flatters fast-growing firms whose growth will not persist.

Sources

  • Lynch P. One Up on Wall Street. Simon & Schuster, 1989 — the source of the "fairly priced at a multiple equal to its growth rate" rule this ratio operationalises.
  • Damodaran A. Investment Valuation — the standard treatment of why PEG is a screening heuristic rather than a valuation, and of its bias toward high-growth firms.

What can make this go out of date

  • Nothing is fetched. The growth rate is an analyst estimate supplied by the user and is the least stable input in the calculation — it is revised continually, and the ratio moves with it far more than with the price.
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