Graham Number Calculator

Use our Graham Number Calculator to find the Graham Number — Benjamin Graham’s conservative estimate of the most a defensive investor should pay for a share, based on its earnings and book value.

The Graham Number is √(22.5 × earnings per share × book value per share). The 22.5 comes from Graham’s two limits: no more than 15 times earnings and no more than 1.5 times book value. The Graham Number sits between the two prices those limits allow.

Add the current share price to see your margin of safety — how far the price is below or above the Graham Number — and whether the stock passes Graham’s P/E and P/B tests. The formula only works for profitable companies with positive book value.

It’s a quick screening tool, not a buy or sell signal: it leaves out growth, debt and the quality of the business, so treat the results as an estimate. To check a dividend stock’s income, use our Stock Yield Calculator.