How to Calculate Graham Number: Ben Graham's Formula Explained

Last Updated: February 22, 2026

The Graham Number is the most famous stock valuation formula in history — created by Benjamin Graham, the "father of value investing" and Warren Buffett's mentor at Columbia Business School.

This simple formula has guided successful investors for over 70 years, helping them identify undervalued stocks and avoid overpaying for popular companies. Best of all? You can calculate it for any stock in under 30 seconds.

In this complete guide, we'll show you exactly how the Graham Number works, when to use it, and how it can improve your investment returns. No complex math or financial jargon — just practical knowledge you can use immediately.

What is the Graham Number? (Simple Explanation)

The Graham Number is a quick way to estimate the maximum price you should pay for a stock based on its earnings and book value.

Ben Graham believed that conservative investors should never pay more than a certain multiple of:

What the company earns (earnings per share)
What the company owns (book value per share)

His formula combines these factors into one number — the Graham Number — representing the stock's fair value.

The Graham Number Formula:

Graham Number = √(22.5 × EPS × BVPS)

Where:

EPS = Earnings Per Share (last 12 months)
BVPS = Book Value Per Share
22.5 = Graham's magic number (15 × 1.5, explained below)

Real Example: Apple Inc. (AAPL)

Let's calculate Apple's Graham Number using recent data:

EPS: $6.05
BVPS: $4.40

Calculation: Graham Number = √(22.5 × 6.05 × 4.40) = √(599.47) = $24.48

Wait — that seems way too low compared to Apple's stock price of ~$185. Does that mean Apple is wildly overvalued?

Not necessarily. We'll explain why shortly, but first, let's understand where this formula comes from.

The History Behind Graham's Formula

Benjamin Graham developed this formula during the Great Depression and refined it through the 1940s-1960s. He was looking for a mechanical way to identify stocks that were:

Profitable (positive earnings)
Asset-backed (trading at reasonable multiples of book value)
Reasonably priced (not expensive by historical standards)

His original rules were:

Never pay more than 15 times earnings (P/E ≤ 15)
Never pay more than 1.5 times book value (P/B ≤ 1.5)

But Graham realized that a stock might fail one test while passing the other spectacularly. So he created a combined formula where:

15 × 1.5 = 22.5 (the multiplier in his formula)
The square root ensures neither factor dominates completely

Historical context: In Graham's era (1930s-1960s), most stocks traded at P/E ratios of 6-12 and P/B ratios of 0.8-2.0. His 15×/1.5× limits were considered conservative even then.

How to Calculate Graham Number (Step-by-Step)

Step 1: Find the Earnings Per Share (EPS)

Look for "diluted EPS" from the most recent 12-month period (also called "trailing twelve months" or TTM).

Where to find it:

Company's 10-K or 10-Q SEC filings
Financial websites (Yahoo Finance, Google Finance, etc.)
Your broker's research section

Important: Use diluted EPS, not basic EPS. Diluted EPS accounts for stock options and convertible securities, giving a more conservative picture.

Step 2: Find the Book Value Per Share (BVPS)

Book value = Total assets minus total liabilities (also called "shareholders' equity")

Book Value Per Share = Shareholders' Equity ÷ Shares Outstanding

Where to find it:

Company's balance sheet (most recent quarter)
Financial websites often list this as "Book Value/Share"
Some sites call it "Tangible Book Value" (excludes intangible assets like goodwill)

Step 3: Apply the Formula

Graham Number = √(22.5 × EPS × BVPS)

Calculator tip: Most smartphones have a square root function, or just use our free Graham Number calculator at valueofstock.com.

Step 4: Compare to Current Stock Price

Stock price below Graham Number: Potentially undervalued
Stock price above Graham Number: Potentially overvalued
Stock price significantly above: Consider avoiding

Real Examples: Graham Number Calculations

Let's walk through calculations for different types of companies:

Example 1: Bank Stock (JPMorgan Chase)

EPS: $15.00
BVPS: $95.00
Graham Number: √(22.5 × 15.00 × 95.00) = √(32,062.5) = $179.06
Current Price: $165.00
Analysis: Trading below Graham Number — potentially undervalued

Example 2: Utility Stock (Consolidated Edison)

EPS: $4.10
BVPS: $28.50
Graham Number: √(22.5 × 4.10 × 28.50) = √(2,630.25) = $51.29
Current Price: $89.00
Analysis: Trading well above Graham Number — potentially overvalued

Example 3: Industrial Stock (Caterpillar)

EPS: $12.80
BVPS: $45.20
Graham Number: √(22.5 × 12.80 × 45.20) = √(13,017.60) = $114.10
Current Price: $280.00
Analysis: Trading at 2.5x Graham Number — very expensive by Graham's standards

When the Graham Number Works Best

The Graham Number isn't suitable for all stocks. It works best with:

✅ Traditional "Value" Stocks

Banks and financial services
Utilities
Industrial companies
Consumer staples
REITs
Railroad companies

Why it works: These businesses have substantial physical assets, steady earnings, and mature business models similar to companies in Graham's era.

✅ Cyclical Businesses

Mining companies
Oil & gas
Manufacturing
Construction

Why it works: When these industries are out of favor, good companies often trade below their Graham Numbers, creating opportunities.

✅ Dividend-Paying Companies

Mature businesses with consistent earnings
Companies returning cash to shareholders
Established market leaders

Why it works: Dividend payments indicate real, sustainable earnings rather than accounting tricks.

When the Graham Number Doesn't Work

❌ High-Growth Technology Stocks

Why: Companies like Tesla, Netflix, or software companies often have:

Low or negative book values (asset-light business models)
Rapidly growing earnings that make historical EPS less relevant
Competitive advantages that justify higher valuations

Example: Microsoft has a Graham Number around $40, but trades over $400. The formula completely misses the value of Microsoft's software ecosystem, recurring revenue, and dominant market position.

❌ Companies with Intangible Assets

Why: Modern companies derive value from:

Brand recognition (Coca-Cola, Nike)
Intellectual property (patents, trademarks)
Data and network effects (Google, Facebook)
Customer relationships and contracts

These assets don't show up in book value calculations.

❌ Loss-Making Companies

Why: The Graham Number requires positive earnings. Companies with negative EPS can't be valued using this method.

What to do: Wait until they return to profitability, or use other valuation methods.

Advanced Graham Number Strategies

Strategy 1: The "Graham Portfolio" Approach

Screen all stocks for those trading below their Graham Number
Select 15-20 stocks from different industries
Equal-weight positions
Hold for 1-2 years, then rebalance

Historical performance: Studies show this approach has outperformed the market over long periods, especially during bear markets.

Strategy 2: Graham Number + Quality Filters

Don't just buy any stock below its Graham Number. Add quality filters:

✅ Debt-to-equity ratio below 50%
✅ Current ratio above 2.0 (can pay short-term debts)
✅ Positive earnings for at least 5 of last 7 years
✅ Dividend payments not cut in last 5 years

Strategy 3: Graham Number Range Analysis

Instead of using the Graham Number as a precise target, create ranges:

Strong Buy: 0-70% of Graham Number
Buy: 70-85% of Graham Number
Hold: 85-115% of Graham Number
Sell: Above 115% of Graham Number

This accounts for the formula's limitations and market inefficiencies.

Graham Number vs. Other Valuation Methods

Graham Number vs. P/E Ratio

Graham Number: Considers both earnings and assets
P/E Ratio: Only considers earnings
Winner: Graham Number for asset-heavy businesses, P/E for asset-light

Graham Number vs. DCF Analysis

Graham Number: Simple, quick, backward-looking
DCF: Complex, comprehensive, forward-looking
Winner: DCF for accuracy, Graham Number for simplicity

Graham Number vs. Price-to-Book Ratio

Graham Number: Balances earnings and book value
Price-to-Book: Only considers assets
Winner: Graham Number (P/B alone can be misleading)

Smart approach: Use the Graham Number for initial screening, then dig deeper with other methods for your final investment decision.

Common Graham Number Mistakes

Mistake 1: Using Outdated Data

Stock prices change daily, but earnings and book value are only updated quarterly. Make sure you're using the most recent financial data available.

Mistake 2: Ignoring Negative Book Value

Some companies (especially tech companies) have negative book value due to stock buybacks or accumulated losses. The Graham Number can't be calculated for these stocks.

Mistake 3: Not Adjusting for Industry

A Graham Number that seems high for a tech stock might be reasonable for a bank. Consider industry norms and business model differences.

Mistake 4: Forgetting About Quality

The cheapest stocks (lowest relative to Graham Number) are often cheap for good reasons — declining businesses, major problems, or structural challenges.

Mistake 5: Market Timing Expectations

Even if a stock is trading below its Graham Number, the market might take months or years to recognize that value. Be patient.

Graham Number in Today's Market Environment

Challenge: Inflation and Interest Rates

Graham developed his formula during different economic conditions. Today's environment presents challenges:

Higher inflation: Makes historical book values less relevant
Low interest rates: Justified higher stock valuations for years
Rising rates (2022-2026): May make Graham's conservative approach more relevant again

Challenge: Changed Business Models

Modern businesses often have:

Lower asset intensity (software vs. factories)
Higher return on equity
Different competitive dynamics
Intangible value drivers

Opportunity: Market Efficiency

While markets are more efficient than in Graham's era, they still create opportunities:

Short-term thinking by many investors
Algorithmic trading creates technical dislocations
Emotional reactions to news still drive prices

Bottom line: The Graham Number isn't perfect for today's market, but it's still valuable as part of a comprehensive analysis approach.

How to Use Our Free Graham Number Calculator

Ready to start using the Graham Number? Our calculator at valueofstock.com makes it instant and easy:

What You Get:

✅ Instant Graham Number calculation for any stock
✅ Current price vs. Graham Number comparison
✅ Visual "overvalued/undervalued" indicator
✅ Historical Graham Number trends
✅ Industry comparison data

How to Use It:

Enter any stock ticker symbol
Get instant Graham Number and current price
See whether the stock passes Graham's test
Compare to other valuation methods
Make informed investment decisions

Calculate Graham Numbers for free →

Building Your Graham-Inspired Investment Process

Step 1: Set Your Criteria

Decide your Graham Number strategy:

Conservative: Only buy stocks at 70% of Graham Number or less
Moderate: Buy stocks at 85% of Graham Number or less
Aggressive: Buy stocks at 100% of Graham Number or less

Step 2: Create Your Watchlist

Use screening tools to find stocks trading near or below their Graham Numbers:

Focus on industries where the formula works well
Add quality filters to avoid value traps
Update your list monthly

Step 3: Do Additional Research

The Graham Number is your starting point, not your ending point:

Read recent quarterly reports
Understand the business model
Check for major risks or opportunities
Consider management quality

Step 4: Position Sizing and Timing

Start with smaller positions to limit risk
Consider dollar-cost averaging into positions
Set price targets for adding or trimming
Be patient — value recognition takes time

The Warren Buffett Connection

Warren Buffett learned directly from Ben Graham at Columbia and worked at Graham's investment firm. While Buffett evolved beyond strict Graham Number investing, he still uses its principles:

What Buffett Kept from Graham:

Focus on intrinsic value vs. market price
Margin of safety principle
Long-term perspective
Emotional discipline

What Buffett Added:

Quality of business matters more than just cheapness
Willingness to pay fair prices for exceptional companies
Focus on competitive advantages ("moats")
Understanding of brand value and intangible assets

Buffett's famous quote: "I'm 85% Benjamin Graham and 15% Philip Fisher" (Fisher focused on growth and quality).

Beyond the Graham Number: Modern Applications

Enhanced Graham Formula

Some investors modify Graham's formula for modern markets:

Version 1: Adjusted for Growth Graham Number = √(22.5 × EPS × BVPS × (1 + Growth Rate))

Version 2: Tangible Book Value Use tangible book value instead of total book value to exclude goodwill and intangible assets.

Version 3: Normalized Earnings Use average earnings over 5-7 years instead of current year to smooth cyclical effects.

AI-Enhanced Graham Analysis

At valueofstock.com, we combine the Graham Number with modern analytics:

Industry-adjusted benchmarks
Business quality scores
Sentiment analysis
Multiple valuation methods combined

This gives you the wisdom of Graham's approach with the power of modern technology.

The Bottom Line: Should You Use the Graham Number?

Yes — but as part of a complete investment process, not as your only tool.

Use the Graham Number to:

✅ Initial stock screening
✅ Identify potentially undervalued companies
✅ Avoid obviously overpriced stocks
✅ Maintain discipline during market bubbles

Don't rely on it for:

❌ High-growth technology stocks
❌ Asset-light business models
❌ Companies with significant intangible value
❌ Precise timing of buy/sell decisions

The Smart Approach:

Screen with the Graham Number
Analyze with multiple valuation methods
Research the business fundamentals
Invest with appropriate position sizing
Monitor and adjust over time

Getting Started Today

Ready to put the Graham Number to work? Here's your action plan:

This Week:

Calculate Graham Numbers for 5 stocks you own
Compare results to current prices
Identify any obvious overvaluations in your portfolio

Next Week:

Screen for stocks trading below their Graham Numbers
Research 2-3 candidates that pass quality filters
Start a watchlist for future opportunities

Next Month:

Consider making your first Graham-inspired investment
Track how Graham Number stocks perform vs. your other holdings
Refine your process based on what you learn

Ready to get started? Use our free Graham Number calculator for any stock instantly at valueofstock.com.

Benjamin Graham's wisdom has created countless millionaire investors. While markets have evolved, the core principle remains: buy stocks for less than they're worth. The Graham Number is your first step toward that goal.