Graham Number Calculator: How to Find Undervalued Stocks the Benjamin Graham Way

If you've spent any time in value investing circles, you've heard the name Benjamin Graham. But knowing about Graham and actually using his methods to find undervalued stocks are two different things. The Graham Number is one of the most practical tools he left behind — a single formula that distills decades of fundamental analysis wisdom into a number you can compare directly to a stock's price.

In this post, we'll break down exactly what the Graham Number is, why the math behind it makes sense, walk through a real-world example with a well-known blue-chip stock, and show you how to plug it into a broader value investing framework. You can also skip straight to our free Graham Number Calculator and run the numbers yourself in seconds.

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Who Was Benjamin Graham?

Benjamin Graham (1894–1976) was an economist, professor, and investor widely regarded as the father of value investing — the discipline of buying stocks trading below their intrinsic worth. His books Security Analysis (1934) and The Intelligent Investor (1949) remain essential reading for serious investors, and his most famous student, Warren Buffett, has called Graham's framework the foundation of everything he's built.

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What Is the Graham Number?

The Graham Number is a ceiling price — the maximum price a defensive investor should pay for a stock based on its earnings and book value. If a stock trades below its Graham Number, it may be undervalued. If it trades above, it may be overpriced relative to Graham's conservative standards.

The formula is:

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

That's it. Two inputs, one square root, one number to compare against the current stock price.

Breaking Down the Inputs

• EPS (Earnings Per Share): The company's net income divided by shares outstanding, typically the trailing twelve months (TTM).
• Book Value Per Share (BVPS): Total shareholders' equity divided by shares outstanding. This is the accounting value of the company on a per-share basis — what shareholders would theoretically receive if the company liquidated.

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Why 22.5? The Logic Behind the Multiplier

The number 22.5 isn't arbitrary. It comes directly from two valuation benchmarks Graham considered reasonable for a defensive investor:

• Maximum P/E ratio: 15× — Graham believed a stock should not trade at more than 15 times earnings.
• Maximum P/B ratio: 1.5× — A stock shouldn't trade at more than 1.5 times its book value.

Multiply those two limits together:

15 × 1.5 = 22.5

So the Graham Number essentially asks: What price would put this stock at exactly a 15 P/E and a 1.5 P/B simultaneously? Anything below that price is, by Graham's standards, within the margin of safety.

This dual-metric approach is part of what makes the Graham Number more robust than looking at P/E or P/B alone. A company can look cheap on one metric and expensive on another — the Graham Number forces both into a single threshold.

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Step-by-Step Worked Example: Johnson & Johnson (JNJ)

Let's run through the Graham Number calculation using Johnson & Johnson — a classic blue-chip stock that Graham-style investors have studied for decades.

(Note: The figures below are illustrative examples for educational purposes. Always use current data from financial statements before making any investment decisions.)

Step 1: Find the EPS

Johnson & Johnson's trailing twelve-month EPS: $8.72

Step 2: Find the Book Value Per Share

Total shareholders' equity divided by diluted shares outstanding: $26.10 per share

Step 3: Plug Into the Formula

Graham Number = √(22.5 × 8.72 × 26.10)

= √(22.5 × 227.59)

= √5,120.78

≈ $71.56

Step 4: Compare to the Current Price

If JNJ is trading at, say, $155, the stock is trading at more than 2× its Graham Number. That doesn't necessarily mean JNJ is a bad investment — it means the market is assigning significant value beyond what Graham's conservative formula captures.

Conversely, if you find a stock trading at $60 with a Graham Number of $85, that $25 gap is your margin of safety — the buffer Graham always insisted on before buying.

You can run this calculation instantly using our Graham Number Calculator. Just enter the EPS and Book Value Per Share, and it handles the math.

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When the Graham Number Works Well

The Graham Number shines in specific contexts:

1. Mature, asset-heavy businesses Utilities, industrials, and consumer staples companies tend to have stable earnings and meaningful book values. For these, book value is a reliable anchor, and the formula gives you a useful floor price.

2. Cyclical stocks at trough earnings When a cyclical company (think automakers or steel producers) is at the bottom of a business cycle, its earnings are depressed. A patient value investor can use the Graham Number with normalized earnings to identify whether the stock is genuinely cheap.

3. Finding a starting shortlist Even when you're not buying purely on the Graham Number, it's an excellent filter. Run our stock screener to surface stocks trading near or below their Graham Number, then dig deeper into the ones that look interesting.

4. Sanity-checking a potential purchase If a stock you're researching trades at 4× its Graham Number, that's a signal to ask hard questions. Maybe the growth justifies it — but you should be conscious of the premium you're paying.

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When the Graham Number Doesn't Work

Be honest about the formula's limitations:

1. High-growth technology companies A company like Nvidia or Salesforce generates most of its value from future earnings expectations, not current book value. Their book values are relatively small compared to their earnings power and intellectual property. The Graham Number will almost always make these stocks look wildly overvalued — which misses the point of what you're actually buying.

2. Financial companies (banks, insurers) Ironically, even though book value is meaningful for financials, the leverage and complexity in their balance sheets make BVPS less reliable as a "what's left if we shut down" figure. Loan loss reserves, off-balance-sheet items, and derivatives can all distort the picture. Use the Graham Number here, but verify carefully.

3. Companies with negative book value Buybacks and accumulated losses can push book value negative (think companies that have aggressively repurchased shares). A negative BVPS makes the formula mathematically unusable.

4. Companies with recent earnings distortions A one-time write-off or gain can spike or crater EPS for a year. Using distorted TTM EPS gives you a misleading Graham Number. Always check whether earnings are representative of ongoing operations.

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Using the Graham Number Alongside Other Metrics

No single metric tells the whole story. The Graham Number is most powerful when it's one piece of a broader fundamental picture:

Price-to-Earnings (P/E) Ratio

The P/E ratio shows how much you're paying for each dollar of earnings. If a stock's P/E is below 15 and it's near or below its Graham Number, that's a double signal of potential undervaluation. Our stock screener lets you filter by P/E alongside Graham Number estimates.

Price-to-Book (P/B) Ratio

Since Graham Number embeds a 1.5× P/B ceiling, checking P/B directly confirms the calculation. A P/B under 1.0 — meaning the stock trades below accounting value — is often a strong value signal on its own, especially for financial companies.

Dividend Yield

Graham preferred companies that paid dividends. A high dividend yield (relative to historical averages or sector peers) often signals a stock the market has beaten down — exactly the kind of situation where the Graham Number might show a discount too. A dividend yield above 3–4% combined with a below-Graham-Number price is a compelling combination.

Return on Equity (ROE)

Book value matters a lot more if the company is doing something productive with it. Look for companies with consistent ROE above 10–15%. A stock trading below its Graham Number and generating solid returns on equity is a much more interesting opportunity than one that's cheap simply because it's destroying value.

Debt-to-Equity Ratio

Graham was deeply wary of leverage. Before acting on a Graham Number signal, check whether the company carries excessive debt. High debt doesn't just increase risk — it can make book value misleading, since liabilities reduce equity but don't always reduce earnings power proportionally.

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How to Use Our Free Graham Number Calculator

The fastest way to apply all of this is to use our free tool. Here's how:

1. Look up EPS — Find the trailing twelve-month EPS from any financial data provider (Yahoo Finance, Macrotrends, etc.) or pull it directly from the income statement.
2. Look up Book Value Per Share — Find this on the balance sheet (shareholders' equity ÷ diluted shares outstanding).
3. Enter both numbers into our Graham Number Calculator.
4. Compare the result to the current stock price.
5. Dig deeper on anything trading below or near its Graham Number — run it through the broader checklist above before making any decisions.

You can also browse the rest of the Value Investing blog for deeper dives into other fundamental analysis metrics, screening strategies, and stock valuation frameworks.

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The Bottom Line

The Graham Number is one of the clearest, most actionable tools in value investing. In a single formula, it combines earnings power and asset value into a price ceiling — and if a stock is trading well below that ceiling, it's worth a closer look.

It won't tell you everything. High-growth companies will almost always fail the test. Companies with noisy balance sheets need extra scrutiny. But for finding solid, profitable businesses trading at reasonable prices — the kind of investments Benjamin Graham spent his career hunting — the Graham Number remains as useful today as when he first described it.

Ready to run the numbers? Use our free Graham Number Calculator to analyze any stock in under a minute.

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Disclaimer: This article is for educational and informational purposes only and does not constitute investment advice. The worked examples use illustrative figures and should not be relied upon for actual investment decisions. Always conduct your own research and consult a qualified financial advisor before investing. Past performance is no guarantee of future results.