π P/B Ratio Calculator
What you pay for each dollar of net assets.
Share price divided by book value per share
Estimates for planning only, not financial advice.
The price-to-book ratio divides share price by book value per share: what you pay versus the accounting value of net assets behind each share. A P/B of 3.75 means paying $3.75 for each $1 of book value. Graham and the classic value investors lived on this ratio, hunting stocks near or below book value. It still works best where assets are real and countable.
How to Use This Calculator
Enter the share price and book value per share (total shareholder equity divided by shares outstanding, from the latest balance sheet). The calculator returns the multiple and the premium or discount to book value.
Enter share price and book value per share. Use tangible book value if you want to exclude goodwill.
Read the P/B and the premium to book. Below 1.0 means the market values the company under its accounting net worth.
Ask whether book value is real. For earnings-based cross-checks, see our P/E ratio calculator.
The P/B Formula
Book value is an accounting construct: assets minus liabilities at historical cost less depreciation. For banks, insurers, and REITs it tracks economic reality closely. For software and brand businesses it is nearly meaningless, because their real assets (code, customers, talent) never touch the balance sheet.
Worked Example
A bank stock trades at $150 with book value per share of $40. The P/B is 3.75, a 275 percent premium to book. That premium says the market expects the bank to earn well above its cost of equity on that book value for years. If a peer bank trades at 1.2 times book with similar returns, the first bank needs a convincing edge to justify the gap.
Reading Your Result
Below 1.0 can signal a bargain or a value trap: the market may doubt the assets are really worth book. Banks below book often carry hidden loan losses; manufacturers below book may own obsolete plants. Above 3.0, you are paying mostly for franchise value and future returns, not for assets in hand.
My rule: P/B works when book value means something. For financials and asset-heavy industrials, it is a first-class metric. For asset-light businesses, ignore it entirely and use earnings or cash flow multiples. The worst mistakes come from applying a book-value lens to companies whose value was never on the balance sheet. To see what the assets actually earn, pair it with return on equity, or check operating efficiency with the asset turnover calculator.
Book value's weakness is that accounting was designed for factories, not franchises. R&D, brands, and network effects, the actual sources of value in modern companies, mostly never appear as assets, so P/B systematically overstates the expensiveness of asset-light businesses. For banks and insurers, where the assets are financial and marked honestly, P/B remains the primary valuation yardstick.
Watch for buyback distortion. Repurchases above book value shrink equity and inflate P/B; sustained programs can drive book value near zero and the ratio into the stratosphere. When P/B looks absurd, check whether the company simply bought back its own equity. The ratio measures accounting artifacts as much as value.
Estimates for planning only, not financial advice.
Frequently Asked Questions
What is the price-to-book ratio?
The P/B ratio is share price divided by book value per share. It compares what the market charges for the stock against the accounting value of net assets per share. A P/B of 1.0 means paying exactly book value; 3.75 means paying nearly four times book.
How do you calculate book value per share?
Divide total shareholder equity from the balance sheet by shares outstanding. Some investors use tangible book value, which subtracts goodwill and intangibles, for a stricter asset measure. Check the balance sheet date: stale equity figures make the ratio stale too, so use the latest quarterly filing.
What is a good P/B ratio?
Below 1.0 has traditionally screened as cheap, and the broad market averages around 2.5 to 3.5. But the right level depends on returns: a bank earning 15 percent on equity deserves a higher P/B than one earning 6 percent. Compare within the sector against return on equity.
Why do value investors like P/B?
It anchors price to something countable. Graham's net-net strategy bought stocks below net current asset value, a deep-value extreme of P/B thinking. Even today, P/B below 1.0 flags candidates where the market prices in distress that may be overdone. Net-nets barely exist in efficient markets now, but the P/B < 1 screen still surfaces interesting distress.
When is P/B misleading?
For asset-light businesses whose value is intellectual property, brands, or network effects, book value understates true worth and P/B overstates expensiveness. It also misleads when assets are carried at stale historical costs far from market value, in either direction. R&D-intensive firms look expensive on P/B because accounting expenses their crown jewels instead of capitalizing them.
What is tangible book value?
Book value minus goodwill and other intangible assets. It answers what hard assets back each share. Banks are often valued on tangible book because goodwill from acquisitions can inflate reported equity without adding loss-absorbing capacity. Price-to-tangible-book under 1.0 for a profitable bank usually means the market fears hidden loan losses.
Can P/B be negative?
Yes, when shareholder equity is negative from accumulated losses or massive buybacks. The ratio is meaningless then; a negative P/B is not a bargain signal. Switch to enterprise-value multiples or earnings measures instead. Tobin's Q is the macro cousin: market value over replacement cost of assets.
How does P/B relate to ROE?
Closely. In theory, P/B equals (ROE minus growth) divided by (cost of equity minus growth). Companies earning above their cost of equity deserve P/B above 1.0; those earning below it deserve discounts. High ROE with low P/B is the classic value screen.
Do buybacks affect P/B?
Yes. Buybacks above book value shrink equity and raise P/B; buybacks below book value do the reverse. Heavy buyback programs can push book value near zero, making P/B astronomical and useless. Check the trend, not just the snapshot. Apple's book value went deeply negative from buybacks while the business thrived: the ratio said nothing.
Is P/B still relevant today?
For financials, REITs, and asset-heavy industrials, absolutely. For the modern economy's asset-light giants, much less so. The ratio did not stop working; the economy shifted toward businesses whose value it cannot see. Use the right multiple for the business in front of you.