Graham Number Calculator
Calculate the maximum fair price for a stock using Benjamin Graham's value investing formula to find undervalued stocks.
Understanding the Graham Number: Complete Guide
The Graham Number is a fundamental value investing metric created by Benjamin Graham, widely regarded as the father of value investing and mentor to Warren Buffett. This powerful formula helps investors determine the maximum price they should pay for a stock based on its earnings and book value.
What is the Graham Number?
The Graham Number represents the upper limit of what a defensive investor should pay for a stock. It combines two of Graham's core principles: that a stock's price-to-earnings (P/E) ratio should not exceed 15, and its price-to-book (P/B) ratio should not exceed 1.5. When you multiply these limits (15 x 1.5 = 22.5), you get the famous Graham multiplier.
A stock trading below its Graham Number may be considered undervalued and a potential buying opportunity, while a stock trading above it may be overvalued.
The Graham Number Formula
Where:
- 22.5: The Graham multiplier (15 x 1.5)
- EPS: Earnings Per Share (Net Income / Shares Outstanding)
- BVPS: Book Value Per Share (Shareholders' Equity / Shares Outstanding)
The Logic Behind 22.5
The number 22.5 comes from Graham's two fundamental requirements:
| Criterion | Maximum Ratio | Reasoning |
|---|---|---|
| Price-to-Earnings (P/E) | 15 | Historically reasonable multiple for quality stocks |
| Price-to-Book (P/B) | 1.5 | Limits premium paid over tangible assets |
| Combined (P/E x P/B) | 22.5 | 15 x 1.5 = 22.5 |
Example Calculation
Let's calculate the Graham Number for a stock with:
- Earnings Per Share (EPS): $5.00
- Book Value Per Share (BVPS): $40.00
- Current Price: $50.00
Calculation:
Graham Number = √(22.5 x $5.00 x $40.00)
Graham Number = √(4,500) = $67.08
Analysis: Since the current price ($50) is below the Graham Number ($67.08), this stock may be undervalued with a 34% margin of safety.
Interpreting the Graham Number
| Scenario | Interpretation | Action |
|---|---|---|
| Price < Graham Number | Potentially undervalued | Consider buying (with further analysis) |
| Price = Graham Number | Fairly valued | Hold if owned; wait for better entry |
| Price > Graham Number | Potentially overvalued | Consider selling or avoiding |
Margin of Safety
Benjamin Graham emphasized the importance of a "margin of safety" - buying stocks significantly below their intrinsic value to protect against errors in analysis or unforeseen events. The formula for margin of safety is:
Graham typically recommended a margin of safety of at least 30-50% for defensive investors.
How to Calculate EPS and BVPS
| Metric | Formula | Where to Find |
|---|---|---|
| EPS | Net Income / Shares Outstanding | Income Statement (often pre-calculated) |
| BVPS | Shareholders' Equity / Shares Outstanding | Balance Sheet |
| Shareholders' Equity | Total Assets - Total Liabilities | Balance Sheet |
Limitations of the Graham Number
- Doesn't work for all stocks: Companies with negative earnings or book value cannot be evaluated
- Ignores growth: The formula doesn't account for future earnings growth
- Historical data: Uses backward-looking financial metrics
- Industry differences: Some industries naturally have higher P/E or P/B ratios
- Quality factors: Doesn't consider competitive advantages, management quality, or moats
When to Use the Graham Number
The Graham Number works best for:
- Stable, mature companies with consistent earnings
- Value-oriented stocks rather than growth stocks
- Initial screening to filter potential investments
- Conservative investors seeking downside protection
Graham's Other Investment Criteria
Benjamin Graham's complete investment approach includes additional criteria beyond the Graham Number:
- Adequate Size: Prefer larger companies for stability
- Strong Financial Condition: Current assets should be at least 2x current liabilities
- Earnings Stability: Positive earnings in each of the past 10 years
- Dividend Record: Uninterrupted dividends for 20+ years
- Earnings Growth: At least 33% increase in EPS over 10 years
- Moderate P/E: Price no more than 15x average 3-year earnings
- Moderate P/B: Price no more than 1.5x book value
Frequently Asked Questions
What is a good Graham Number?
A "good" Graham Number is one that exceeds the current stock price, indicating potential undervaluation. The greater the difference between the Graham Number and current price, the larger the margin of safety. Ideally, look for stocks trading at least 30-50% below their Graham Number.
Can the Graham Number be used for all stocks?
No. The Graham Number requires positive EPS and BVPS. It's not suitable for growth stocks, companies with negative earnings, or asset-light businesses. It works best for established, profitable companies with significant tangible assets.
How often should I recalculate the Graham Number?
Recalculate quarterly when new financial statements are released, as EPS and BVPS change over time. However, for stable companies, annual calculations may be sufficient.
Is the Graham Number still relevant today?
While some argue that modern markets have changed since Graham's era, the core principles of buying quality companies at reasonable prices remain timeless. Many successful investors, including Warren Buffett, still use Graham's value investing principles.
What's the difference between Graham Number and intrinsic value?
The Graham Number provides a maximum fair price based on current fundamentals, while intrinsic value calculations (like DCF) attempt to estimate true worth based on projected future cash flows. The Graham Number is simpler but more conservative.