To determine equity in a business, subtract total liabilities from total assets. That single subtraction gives you book value equity, the residual belonging to the owners after every creditor is paid. The work is not the arithmetic. It’s assembling defensible numbers on both sides, then deciding whether book value answers your question or whether you need a fair-market figure that reflects what the ownership stake would actually sell for.
The Formula and What It Gives You
Assets minus liabilities equals equity. A company with $2 million in assets and $750,000 in liabilities has $1.25 million in equity. On a corporate balance sheet, that figure typically breaks into contributed capital (what owners put in), retained earnings (profits kept in the business), and sometimes treasury stock or accumulated other comprehensive income.
Book value is a floor. It tells you what the accounting records say the owners’ interest is worth based on historical cost and accumulated earnings. For asset-heavy businesses like manufacturing or real estate holding companies, book value tracks reasonably close to economic reality. For service firms, tech companies, and any business whose value comes from earning power or intellectual property, book value usually understates what a buyer would pay.
Valuing the Assets
Start with documentation for everything the business owns. Bank statements cover cash. Aging reports cover receivables. Inventory records should reflect current stock valued at cost or the lower current market price, whichever applies. Liquid assets are the easiest to pin down.
Fixed assets take more effort. Real estate needs a recent tax assessment or a professional appraisal. Vehicles have title documents and can be checked against market pricing guides. Machinery, specialized equipment, and fixtures should be supported by purchase contracts or appraisal reports. Physical asset appraisals typically run from a few thousand dollars to well above $10,000, depending on complexity and count.
Depreciation matters more than owners often realize. The IRS requires records establishing the business use of any depreciable property, and your basis in each asset must be reduced by the depreciation allowed or allowable, whichever is greater.1Internal Revenue Service. Publication 946 (2025), How To Depreciate Property An asset register that tracks original cost, method, useful life, and accumulated depreciation for each item keeps the numbers current.
Intangible assets round out the asset side. Patents, trademarks, customer lists, and proprietary software are generally recorded at acquisition cost. If the business developed these internally, the recorded value may be minimal even where the economic value is substantial. That gap is the main reason book value alone rarely captures what a business is worth.
Accounting for Every Liability
The liability side needs the same rigor. Current liabilities come due within twelve months: accounts payable, accrued wages, short-term loans, credit card balances, and taxes owed. Payroll records and quarterly tax filings are the source documents for accrued tax obligations. The IRS requires businesses to keep employment tax records for at least four years after filing the fourth quarter return for the year.2Internal Revenue Service. Employment Tax Recordkeeping
Long-term liabilities extend past twelve months. Mortgages, equipment financing, term loans, and any bonds issued belong here. Pull amortization schedules so you’re using current outstanding balances rather than original face values.
Contingent liabilities are where owners often trip. A pending lawsuit, warranty obligation, or regulatory dispute counts as a liability when the loss is both probable and reasonably estimable. A $200,000 lawsuit with a strong chance of adverse judgment belongs on the balance sheet even though no check has been written. Environmental cleanup follows the same logic.
Deferred revenue is a liability too. Money customers have prepaid for goods or services you haven’t delivered is a future obligation, not profit. Booking it correctly keeps equity from being overstated.
When Book Value Isn’t What You Need
Book value works for internal reporting, loan covenants, and any question that turns on the accounting records themselves. If you’re selling the business, buying out a partner, gifting an interest, or valuing an estate, you need fair market value: the price a willing buyer and willing seller would agree on, neither under pressure, both with reasonable knowledge of the facts.3Internal Revenue Service. Publication 561, Determining the Value of Donated Property Professional appraisers and the IRS both recognize three approaches to getting there.
Asset-Based Approach
Adjust every asset and liability on the balance sheet to current fair market value rather than historical book value, then subtract. This works best for holding companies, real estate firms, and businesses being liquidated. The IRS lists the fair market value of a business’s assets, including goodwill, as one of the factors to consider when valuing a closely held business.3Internal Revenue Service. Publication 561, Determining the Value of Donated Property
Income Approach
This method values the business based on its ability to generate future cash. A discounted cash flow analysis projects free cash flows over five to ten years, estimates a terminal value beyond that, and discounts everything back to present value using a rate that reflects the risk. The discount rate typically comes from the weighted average cost of capital or the required return on equity. This is the dominant approach for profitable, growing companies because it captures earning power the balance sheet ignores.
For smaller businesses, a simpler version uses seller’s discretionary earnings (SDE) multiplied by an industry-specific factor. SDE multiples for small businesses commonly fall between two and four times earnings, depending on industry, growth, and how dependent the business is on the current owner.
Market Approach
The market approach compares the business to similar companies that have recently sold or are publicly traded, using ratios like enterprise value to EBITDA. The value of this approach depends entirely on finding genuinely comparable businesses, which is harder than it sounds for small private companies. A local plumbing company isn’t comparable to a publicly traded conglomerate, and broad sector averages can mislead when applied to a specific small business.
Discounts That Change the Number
If the interest being valued is less than 100% of the company or can’t be easily sold, raw valuation numbers get adjusted downward.
Minority Interest Discount
A stake under 50% commands a lower per-unit price than a controlling interest because the holder can’t unilaterally direct decisions, force distributions, or sell the company. Empirical data and court decisions place this discount between 15% and 45% for small-to-midsize private companies, with courts increasingly skeptical of discounts above 35% absent strong supporting facts. The court-accepted central tendency sits in the mid-20% range.
Discount for Lack of Marketability
Private company shares can’t be sold on an exchange, so converting them to cash takes time and effort. The discount for lack of marketability (DLOM) captures that illiquidity. Restricted stock studies show average discounts of 20% to 35%. Pre-IPO studies show 40% to 60%. Most appraisers apply a DLOM between 15% and 40%, depending on the company’s characteristics, transfer restrictions, and how realistic a future sale looks.
These discounts stack. A 30% interest carrying a 25% DLOM and a 20% minority discount ends up worth far less per share than a simple proportional slice of enterprise value would suggest. That is where valuation disputes get heated, particularly in divorce cases and partner buyouts.
What the Operating Agreement May Override
For LLCs and partnerships, the operating agreement often dictates how equity is valued and transferred, sometimes overriding what a standard appraisal would produce. If you’re calculating equity for a buyout or a departure, read the agreement first.
Well-drafted agreements address what events trigger a mandatory buyout (death, disability, bankruptcy, voluntary withdrawal), how the departing member’s interest gets valued, whether the company or remaining members hold a right of first refusal, and how disputes over value get resolved. Some agreements lock in a formula based on a multiple of revenue or earnings. Others require an independent appraisal. A few specify book value, which can produce results very different from fair market value.
Watch for built-in discounts. A 15% redemption discount written into an operating agreement means a departing member receives 85 cents on the dollar of fair market value regardless of what an appraiser says. Some agreements also stretch payment over several years rather than requiring a lump sum, which reduces the present value of what the departing member actually receives. If the agreement is silent, state law fills the gap, and default rules vary considerably.
What the IRS Cares About
The IRS pays attention to business equity valuations when the business is sold, when interests are gifted, on estate tax returns, and on charitable donations of business interests.
When a business changes hands as an asset acquisition, both buyer and seller must file Form 8594 with their tax returns for the year of sale. The purchase price gets allocated across seven asset classes, from cash (Class I) through goodwill and going concern value (Class VII).4Internal Revenue Service. Instructions for Form 8594, Asset Acquisition Statement Under Section 1060 Under IRC Section 1060, the residual method fills lower-class assets at fair market value first, and whatever remains gets assigned to goodwill. A written allocation between buyer and seller binds both parties unless the IRS finds it inappropriate.5Office of the Law Revision Counsel. 26 US Code 1060 – Special Allocation Rules for Certain Asset Acquisitions
Valuation misstatement penalties have two tiers. If the claimed value is 150% or more of the correct value, the penalty is 20% of the resulting tax underpayment.6Office of the Law Revision Counsel. 26 US Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments If the claimed value is 400% or more of the correct value, the penalty doubles to 40%.7eCFR. 26 CFR 1.6662-5 – Substantial and Gross Valuation Misstatements Under Chapter 1 The substantial misstatement penalty doesn’t apply unless the underpayment attributable to the misstatement exceeds $5,000, or $10,000 for C corporations. A qualified appraisal following recognized methodology gives you a reasonable cause defense if the number is later challenged.
When to Bring in a Professional
You can calculate book value equity yourself with accurate financial statements. Anything beyond that typically calls for professional help, and the IRS says as much: because of the many factors involved in valuing a closely held business, “the help of experts is usually required.”3Internal Revenue Service. Publication 561, Determining the Value of Donated Property
The three most recognized appraisal credentials are the Accredited Senior Appraiser (ASA) from the American Society of Appraisers, the Certified Valuation Analyst (CVA) from the National Association of Certified Valuators and Analysts, and the Accredited in Business Valuation (ABV) from the American Institute of CPAs. Each requires demonstrated experience, examination, and peer-reviewed report submissions.
Fees range widely. A straightforward valuation for a small company with clean financials may start around $2,000 to $5,000. Complex valuations involving multiple entities, significant intangibles, or litigation support can run $50,000 or more. Scope drives the price far more than any hourly rate. Before engaging an appraiser, get a clear engagement letter specifying the valuation standard (fair market value, fair value, or investment value), the approaches used, the deliverable, and the total fee estimate.
The IRS weighs several factors when evaluating a business interest: net worth, earning power, the nature and history of the business, the economic outlook for the industry, the fair market value of assets including goodwill, and comparable sales.3Internal Revenue Service. Publication 561, Determining the Value of Donated Property A good appraisal report addresses each of these, which is what you’ll want if the valuation ever faces scrutiny.