Price-to-Book Ratio Calculator

Created by Arunangshu DasReviewed Nov 9, 2026

Calculate P/B using matching per-share figures or aggregate common equity values.

Use matching common equity coverage and currency units.

Per-share P/B

Enter matching market and book values or load the worked example.

P/B is a dimensionless multiple. Book equity is an accounting measure. Use common equity after any necessary exclusions.

Understand the common book denominator

Reconcile the two input modes and see how zero book value differs from a deficit.

Read the complete Price-to-Book Ratio guide

Formula and methodology

P/B = common share price ÷ common book value per share, or common market cap ÷ common book equity, when book value is positive.

Divide positive common share price by positive common book value per share, or divide positive common market capitalisation by positive common book equity. Use matched currency units and common equity coverage.

Definitions

P/B compares market value for common shareholders with the corresponding accounting book equity. Book value per share is common book equity divided by the relevant period-end common shares.

Verified worked examples

A common share price of 15 and book value of 10 per share give 1.50×. If the same 20 million common shares underlie both values, common market cap of 300 million and book equity of 200 million also give 1.50×.

Interpretation

Zero book value makes P/B undefined. A book deficit gives no meaningful conventional P/B multiple. A positive ratio below one means the market value is below the supplied accounting value. Assess the reasons before drawing any valuation conclusion.

Inputs and interpretation

Choose per-share figures or aggregate common equity. Enter positive market value and signed common book value. Switching input basis clears both fields. Note the quote date and balance-sheet date.

Assumptions and limitations

Use the same issuer, common equity coverage and currency scale. Start with equity attributable to common holders, after any applicable exclusions. Check for share issues, buybacks and splits between the reporting date and quote date.

Supported domain and common mistakes

Use up to 48 trimmed characters and 12 fractional places, with magnitude at most 10^15. Positive multiples can range from 10^−27 to 10^27. Display rounds half-even to two decimals and marks small positive values that would round to zero.

Avoid total assets, enterprise value, float-only market cap, diluted EPS shares and duplicate deductions for preferred equity or noncontrolling interests. Keep total units and share units consistent.

Frequently asked questions

How do I calculate P/B?

Divide common share price by positive common book value per share, or use matched common market cap and common book equity.

Which equity amount should I enter?

Use book equity attributable to common shareholders on the same scope as the market figure. Check the issuer's reconciliation before subtracting any preferred or outside claims.

What happens if book value is zero?

The division is undefined. The calculator shows a zero-book state without a multiple.

Can P/B be negative?

Negative book equity describes a deficit. The calculator identifies the deficit and leaves the conventional multiple unavailable.

Can I enter totals in millions?

Yes, if both aggregate figures use the same currency and scale. A market cap of 300 million and book equity of 200 million can be entered as 300 and 200.

Does P/B below one mean the stock is cheap?

It means the supplied market value is below the supplied common book value. Expected profitability, risks and the composition of book equity can affect the gap.

Sources and educational scope

Educational multiple from supplied inputs. No live prices, currency conversion, accounting adjustments, tangible book, liquidation proceeds, target prices or personalized investment advice.

Reviewed 2026-11-09. AI-assisted content under operator editorial responsibility. No independent expert financial review is claimed.