1. Fundamental & Balance Sheet Inputs
Liquidation & Net-Net Working Capital ($ / Share)
2. Graham Valuation & Liquidation Cushion
3. Executive Defensive Value Evaluation
Matrix 1: EPS ($) vs. Book Value ($) on Graham Number ($)
Matrix 2: Share Price ($) vs. Graham Number ($) on Margin of Safety (%)
4. The Benjamin Graham Value Framework
Origin of the 22.5 Graham Number Multiplier
In Chapter 14 of The Intelligent Investor ("Stock Selection for the Defensive Investor"), Benjamin Graham established two classic valuation boundaries to insulate investors from speculative bubbles:
- P/E Ceiling: The price-to-earnings ratio should not exceed 15.0x for past three-year average earnings.
- P/B Ceiling: The price-to-book ratio should not exceed 1.5x of the last reported book value.
Graham noted that an investor could justify a higher P/E if the P/B was exceptionally low, or vice versa, as long as the product of the two ratios did not exceed 22.5 ($15.0 \times 1.5 = 22.5$):
Net Current Asset Value (NCAV)
$\text{NCAV} = \text{Current Assets} - \text{Total Liabilities}$. Purchasing a stock below $\frac{2}{3}$ of NCAV yields Graham's celebrated "cigar-butt" net-net liquidation bargain.
Net-Net Working Capital (NNWC)
$\text{NNWC} = \text{Cash} + (0.75 \times \text{A/R}) + (0.50 \times \text{Inv}) - \text{Total Liabilities}$. Haircuts receivables and inventory to establish an ultraconservative floor.
Defensive Margin of Safety
Buying at a 25% to 33% discount to tangible intrinsic value absorbs forecast errors, recessions, and operational mistakes while preserving downside capital.
5. Frequently Asked Questions
What is the Graham Number and how is it calculated?
The Graham Number is an intrinsic value metric developed by Benjamin Graham, the father of value investing. It calculates the maximum fair price a defensive investor should pay for a stock based on both earnings and tangible book value: Graham Number = sqrt(22.5 * EPS * Book Value per Share).
Where does the constant 22.5 come from in Graham's formula?
In 'The Intelligent Investor', Benjamin Graham recommended that conservative investors avoid stocks where the Price-to-Earnings (P/E) ratio exceeds 15.0 or the Price-to-Book (P/B) ratio exceeds 1.5. Multiplying these two upper thresholds yields 15.0 * 1.5 = 22.5. If P/E * P/B is 22.5 or lower, the stock passes Graham's valuation product filter.
What is the difference between NCAV and NNWC?
Net Current Asset Value (NCAV) subtracts all liabilities (both current and long-term) from total current assets: NCAV = Current Assets - Total Liabilities. Net-Net Working Capital (NNWC) is an even stricter liquidation measure that discounts accounts receivable by 25% and inventories by 50%: NNWC = Cash + (0.75 * AR) + (0.50 * Inventory) - Total Liabilities.
What constitutes an acceptable Margin of Safety?
Graham advocated for purchasing securities at a significant discount to their intrinsic value—typically at least 20% to 33% below the Graham Number or NCAV. This buffer protects investors against business miscalculations, industry recessions, management errors, or economic downturns.
When should the Graham Number NOT be used?
The Graham Number is specifically designed for asset-heavy, profitable, defensive companies such as manufacturers, industrial firms, and utilities. It is not suitable for asset-light businesses, software tech firms with negative tangible book value, high-growth startups with minimal current earnings, or financial institutions holding marked-to-market securities.