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The Graham Number: Benjamin Graham's Deceptively Simple Formula

How a square root formula from 1949 still identifies undervalued stocks better than most algorithms.

Who Was Benjamin Graham?

Benjamin Graham (1894–1976) was Warren Buffett's professor at Columbia University and the intellectual father of value investing. His books The Intelligent Investor (1949) and Security Analysis (1934) remain the most important works in all of finance.

Buffett called him "the second most influential person in my life" after his own father, and credits Graham's framework as the source of every major investing principle he uses.

The Formula

Graham Number = √(22.5 × EPS × Book Value Per Share)

Simple to calculate, remarkably powerful in practice. The 22.5 is derived from Graham's "dual test": no stock should trade above 15× earnings (P/E ≤ 15) AND 1.5× book value (P/B ≤ 1.5). Multiply those limits: 15 × 1.5 = 22.5.

The Graham Number is the maximum price you should ever pay for a stock if you want to avoid overpaying on both earnings and assets simultaneously.

Real-World Examples (2025 Data)

Price vs Graham Number — Selected Stocks (USD, approximate)
Stock EPS BVPS Graham Number Price Verdict
Verizon (VZ) $2.85 $24.50 $39.65 ~$42 Near fair value
JPMorgan (JPM) $18.22 $95.20 $55.85 ~$233 Significantly above
Wells Fargo (WFC) $5.37 $43.60 $45.80 ~$77 Well above
Coca-Cola (KO) $2.47 $6.52 $19.00 ~$67 Way above

The pattern is clear: most large US stocks trade well above their Graham Number. That is not necessarily wrong — Graham's formula was designed for a different era. But when a stock does trade below its Graham Number, it gets your attention.

⚡ Note: Graham Number works best as a screening tool, not a final verdict. VZ near its Graham Number doesn't automatically mean "buy" — check free cash flow generation, debt levels, and competitive position before committing.

When Graham Works Best

Graham's formula was designed for asset-heavy businesses with stable earnings:

  • Banks and financials: P/B ratio has direct meaning for book value of loans
  • Industrial manufacturers: Real physical assets on the balance sheet
  • Utilities: Regulated earnings, predictable cash flows
  • Mature consumer staples: Stable earnings, no valuation speculation
  • Telcos: Heavy infrastructure, consistent dividend

Australian examples where Graham shines: WBC, ANZ, NAB, Telstra (TLS), Insurance Australia (IAG), Computershare (CPU)

When Graham Does NOT Work

Do not use Graham Number for:

  • Software/SaaS: No physical book value. Microsoft's book value is $35/share, true value is ~$500+
  • Asset-light compounders: Visa, Mastercard, S&P Global — moat is entirely intangible
  • High-growth companies: Nvidia, AAPL in growth phase — book value is irrelevant
  • Healthcare/biotech with R&D moats: CSL's true value is in patents, not balance sheet assets

For these, use DCF. The growth assumptions matter far more than current book value.

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The Margin of Safety on Top of Graham

Graham was emphatic: the Graham Number is a ceiling, not a buy price. Always demand a margin of safety.

For most stocks, buy at 25-33% below the Graham Number: - Graham Number = $40 - 25% MoS → Buy below $30 - 33% MoS → Buy below $27

During market corrections, you frequently find high-quality stocks trading at these discounts. The ASX banks (WBC, ANZ) frequently trade near or below Graham Number during credit cycle concerns, while remaining fundamentally sound businesses.

Building a Graham-Based Watchlist

  1. Screen for stocks where Price < Graham Number (Value Calc screener does this automatically)
  2. Verify the EPS is normalised (no one-off gains/losses distorting the figure)
  3. Check book value is real — not inflated by goodwill from overpriced acquisitions
  4. Confirm the business has a durable competitive position
  5. Set a buy price at 25-33% below the Graham Number and wait

The formula itself takes 10 seconds. The discipline to wait for the right price takes years to develop.

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