The Graham Number is a conservative ceiling price built only from reported EPS and BVPS, not a full intrinsic value estimate. Intrinsic value typically discounts future cash flows and incorporates growth, while the Graham Number ignores growth entirely and acts as a floor-style fair price for defensive investors screening for cheapness.

It performs poorly for asset-light businesses such as software, consumer brands, and consulting firms, where most value lives in intangibles that are not on the balance sheet. Reported book value understates true economic capital, so the formula either flags every quality compounder as overvalued or excludes them outright.

Graham wrote the formula specifically for the defensive investor in The Intelligent Investor, the passive shareholder who wants adequate returns without deep analysis. Enterprising investors who do detailed research can relax the 22.5 cap and use richer models such as the Graham growth formula or discounted cash flow.

The Graham Number is a price ceiling, not a buy price. Graham repeatedly recommended buying at least a third below estimated value, so most practitioners apply a 25 to 50 percent discount to the calculated number before considering a purchase. The margin of safety covers errors in EPS, BVPS, and judgment.

The 22.5 multiplier comes from Graham's twin caps of P/E no greater than 15 and P/B no greater than 1.5. Their product is 22.5, so a stock priced at exactly the Graham Number sits on the boundary of both rules. Any meaningful margin of safety pulls the implied multiples below those ceilings.

The square root only returns a real number when EPS and BVPS are both positive. A money-losing firm has no defensive earnings floor, which is exactly the kind of business Graham wanted his defensive investor to avoid. For such cases, switch to a tangible book value screen or wait for sustained profitability.