Graham Number Calculator — formula, example & how it differs from the Graham Formula

What the Graham Number is

The Graham Number is a formula from Benjamin Graham — the investor and teacher often called the father of value investing, and Warren Buffett’s mentor. It estimates the highest price a careful investor might reasonably pay for a stable, profitable company, using only two numbers from its financial statements: earnings per share (EPS) and book value per share (BVPS).

The idea behind it is caution. Graham wanted a single figure that combined how much a company earns with how much it owns, so that a price could be checked against the substance of the business rather than the mood of the market. If a share trades below its Graham Number, it may be worth studying further; if it trades well above, the price is leaning on optimism the raw fundamentals do not yet support.

It is best understood as a rough floor, not a precise valuation. It deliberately ignores growth, cash flow and intangible assets, which keeps it simple but also means it fits some companies far better than others — a point the later tabs return to.

Graham Number vs Graham Formula

This is the single most common point of confusion for beginners, so it is worth settling early. Benjamin Graham is associated with two different valuation methods, and they are not the same tool.

The Graham Number is asset-based. It multiplies earnings by book value, so it rewards companies that are backed by real, tangible assets and priced modestly against them. It says nothing about how fast the business is growing.

The Graham Formula is growth-based. It starts from earnings and scales them up according to expected growth, then adjusts for the prevailing interest rate. It ignores book value entirely and typically produces a higher figure for a growing company.

A practical way to use them together: treat the Graham Number as the cautious lower anchor and the Graham Formula as the more optimistic upper anchor. The gap between the two is itself informative — a very wide gap usually means the market is paying mostly for expected growth rather than present assets.

The formula, explained

The Graham Number is calculated as follows:

Graham Number = √( 22.5 × EPS × BVPS )

Reading it in plain terms: multiply the earnings per share by the book value per share, multiply that result by 22.5, then take the square root.

Where 22.5 comes from

The 22.5 is not arbitrary. Graham suggested that a defensive investor should not pay more than 15 times earnings and not more than 1.5 times book value for a stock. Multiplying those two ceilings together — 15 times 1.5 — gives 22.5. The constant bakes both of Graham’s price limits into a single number, which is why the result behaves like a sensible upper price rather than a target.

The two inputs

• EPS (earnings per share) — the company’s net profit divided by its number of shares. Use a full-year or trailing-twelve-month figure so a single unusual quarter does not distort it.
• BVPS (book value per share) — the company’s shareholder equity divided by its number of shares. It represents the accounting value of what the business owns after subtracting what it owes.

Both inputs must be positive for the formula to work, because you cannot take a meaningful square root of a negative product.

A worked example

Numbers make the method concrete. The example below uses illustrative figures for a stable, asset-heavy company to show each step. (The figures are for demonstration only.)

Take a company with an EPS of $16.59 and a book value per share of $157.10:

• Step 1 — multiply: 22.5 × 16.59 × 157.10 = 58,641 (approximately).
• Step 2 — square root: √58,641 ≈ $242.

So the Graham Number is about $242 per share. If the stock were trading near $195, the price would sit comfortably below the Graham Number — the kind of gap Graham described as a margin of safety. If instead it were trading at $400, the price would be far above what the earnings and assets alone justify, and a cautious investor would want to understand why before paying that premium.

The validity rule that most people miss

The Graham Number is only trustworthy for a certain kind of company, and Graham was explicit about the boundary. The method assumes the stock already trades at reasonable multiples. Specifically, it is reliable when:

• the price-to-earnings (P/E) ratio is 15 or below, and
• the price-to-book (P/B) ratio is 1.5 or below;
• or, as a combined test, P/E × P/B is 22.5 or below.

When a company sits inside these bounds, the Graham Number is a meaningful gauge. When it sits far outside them — which is common for fast-growing or asset-light businesses — the Number will read far below the market price, and that is not a signal the stock is “wrong”; it simply means the Graham method does not fit that company.

This is why a modern technology company can look “expensive” on the Graham Number even when it is a fine business. Its value lives in growth and intangibles, which the formula was never built to capture. Checking the P/E and P/B first tells you whether the Graham Number deserves your attention for that particular stock.

Using the EquityTimer calculator

The EquityTimer Graham calculator does the arithmetic for you and adds the checks described above, so you can focus on interpretation rather than square roots.

• Enter the EPS and book value per share, and the tool returns the Graham Number instantly.
• It also shows the Graham Formula value alongside it, so you can see the conservative and growth-based estimates together rather than confusing the two.
• It runs the P/E and P/B validity check automatically and flags when a stock falls outside Graham’s range, so you are never misled by a number that does not apply.
• It applies a margin-of-safety percentage to suggest a lower “buy below” reference, and works across the Indian, US and other supported markets with the correct currency.

Because the figures are entered manually, you stay in control of the inputs — useful when you want to test a more conservative EPS or a different growth assumption and watch how the estimates move.

Limits and data notes

The Graham Number is powerful precisely because it is simple, but that simplicity comes with real limits worth keeping in mind:

• It ignores growth. A company growing earnings quickly can be worth far more than its Graham Number, and a shrinking company can be worth less.
• It ignores cash flow and debt structure, so two companies with the same EPS and book value look identical to it even if one carries far more risk.
• It understates asset-light businesses — software, brands and services — whose value is not captured on the balance sheet.
• It depends on reported accounting figures, which can be affected by one-off items, write-downs or differing accounting standards across markets.

For these reasons the Graham Number is best used as one lens among several. Read it next to a cash-flow-based method, the company’s own history, and how its P/E and P/B compare with peers. Agreement across methods is more convincing than any single figure — and where they disagree, the disagreement itself is a prompt to dig deeper.

This article is for educational and informational purposes only and is not investment advice. EquityTimer is not a SEBI-registered adviser. Valuation methods rely on assumptions and reported data that may be incomplete or change over time, and no figure here is a recommendation to buy, sell or hold any security. Always do your own research and consult a registered financial adviser before investing.