Home Office Deduction Calculator
Work out both IRS methods on the same set of numbers, then see which one still leaves you ahead after the depreciation you would owe back on a sale.
Home office deduction comparison
Two methods, and they do not measure the same thing
The IRS gives you a choice, and the two choices are not two ways of computing one number. They are two different deals. The simplified method is a flat allowance that requires no records and creates no depreciation. The actual expense method is a real cost allocation that requires records, produces a bigger number, and quietly mortgages part of your future gain.
Most pages compare the two on the current-year deduction and stop there. That comparison is incomplete, because the money you save this April can come back as tax when you sell.
What qualifies before any arithmetic matters
Three conditions gate the whole thing, and failing any one of them means the amount is zero regardless of which method you pick.
Exclusive use. The space is used for business and for nothing else. A desk against the wall of a guest room does not qualify, because the room has a personal function. A converted closet does, because nothing else happens in it.
Regular use. Occasional use is not enough. The space has to be a place you actually work, not a table you open a laptop on twice a month.
Principal place of business. Your home must be where you conduct the main business activity, where you meet clients, or — under the administrative-or-management safe harbour — where you handle billing, scheduling, and recordkeeping with no other fixed location for those tasks. That last route is what lets a contractor who works entirely at job sites still claim a home office.
Employees are excluded. Unreimbursed employee business expenses were suspended from 2018 onward, and the One Big Beautiful Bill Act of 2025 made that suspension permanent rather than letting it lapse. A W-2 worker with a dedicated home office gets nothing on Schedule A, no matter how clean the exclusive-use facts are.
The simplified method: 300 square feet, hard stop
The arithmetic is one line. Take the smaller of your office area or 300 square feet, multiply by $5. The maximum is $1,500, and that ceiling has not moved since the method was introduced for 2013 returns.
The cap is what people underestimate. A 400 square foot office counts as 300. A 900 square foot converted garage counts as 300. The method does not care that you gave up more space, and it does not care that you live in a market where square footage is expensive.
In exchange, four things become simple: no Form 8829, no allocation of every utility bill, no depreciation, and no recapture when the house sells. Home-related itemized deductions — mortgage interest and property tax — stay fully deductible on Schedule A, unreduced by the business percentage.
The actual expense method: allocation and ordering
Divide the office area by the total area to get a business percentage, then apply that percentage to the costs of running the whole house. Indirect costs are shared between personal and business life and get prorated: interest, property tax, insurance, utilities, repairs to common areas, and depreciation on the structure.
Direct costs belong only to the office and are deducted at 100% — repainting the office, a dedicated business phone line, a repair to a window that only the office uses.
Depreciation is the piece that changes the decision. The business percentage of the home's basis is recovered straight-line over 39 years, because a home office is treated as nonresidential real property. On a $420,000 basis with a 10% office, that is $42,000 spread over 39 years, or about $1,077 a year.
The income ceiling that surprises people
Section 280A(c)(5) limits the deduction to the gross income from the business use of the home, reduced by the business expenses that have nothing to do with the home. The practical effect is that a home office cannot turn a profitable Schedule C into a loss.
The two methods treat a shortfall differently. Under the actual expense method, a disallowed amount carries forward and can be used in a later year when income recovers. Under the simplified method, a disallowed amount is gone permanently. For a business with lumpy income — a first year, a slow quarter, a sabbatical — that asymmetry can quietly make the "simpler" method the more expensive one.
Depreciation recapture, in plain terms
Depreciation reduces your basis in the house. When you sell, the gain is measured against that reduced basis, so the depreciation you deducted earlier shows up as gain later. That slice is "unrecaptured section 1250 gain" and is taxed at a maximum federal rate of 25%.
Two details make it worse than it sounds. First, the section 121 exclusion — the $250,000 single and $500,000 joint exclusion on a main home — does not shelter recapture. It shelters appreciation, not depreciation. Second, the rule is "allowed or allowable": depreciation you were entitled to claim is recaptured whether or not you actually claimed it. Skipping the deduction on your return does not skip the tax.
That is the honest argument for the simplified method. It is not that the deduction is bigger, because it usually is not. It is that the simplified method buys a clean exit.
Which method to pick
Three patterns cover most situations. If you rent, take the actual expense method — there is no structure to depreciate, so no recapture, and prorated rent usually beats $1,500. If you own and expect to sell within a few years, the simplified method often wins on an after-tax basis, because the recapture you avoid can exceed the deduction you give up. If you own and expect to stay for a decade or more, run both and compare the extra deduction against the eventual 25% on the depreciation, discounted for the time value.
One more consideration that the arithmetic misses: the actual method requires records. Every bill, every allocation, every year. If you will not keep them, the deduction is not real — it is a position you cannot defend in an audit.
Frequently asked questions
Can I claim a home office if I am a W-2 employee?
No. Unreimbursed employee business expenses have been suspended since 2018, and the One Big Beautiful Bill Act made the suspension permanent rather than letting it expire. Only self-employed filers reporting on Schedule C or Schedule F can claim it.
Is the simplified method always smaller than the actual expense method?
Usually, yes. It caps at $1,500 regardless of housing cost, while the actual method has no dollar ceiling. In an expensive home with high interest and property tax, the prorated share clears $1,500 easily. In a small home with a modest office, the two can land close together.
Why would anyone choose the smaller deduction?
Because the actual method depreciates the business portion of the house, and that depreciation is recaptured at up to 25% on sale — outside the protection of the section 121 exclusion. On a house you plan to sell, the smaller annual deduction can leave you with more after tax.
What does exclusive and regular use actually mean?
The area must be used regularly for business and used for nothing else. A desk in the corner of a bedroom fails, because the room also serves a personal purpose. A spare bedroom used only as an office passes. A detached structure used only for business also qualifies.
Can the deduction create a loss on Schedule C?
No. Section 280A(c)(5) limits it to the gross income from the business use of the home minus other business expenses. Under the actual method the excess carries forward; under the simplified method it is lost.
Which method should I use if I rent?
Renters can prorate rent, renters insurance, and utilities with the actual expense method. Because there is no house to depreciate, there is no recapture risk, which removes the main argument for the simplified method.
Do I file Form 8829 with the simplified method?
No. The simplified method is elected right on Schedule C by entering the home's total square footage and the office square footage in the designated boxes. Form 8829 is only for the actual expense method, where you also work out the carryover of any disallowed amount.
Disclaimer: Nothing here is tax, legal, or financial advice — it is an arithmetic comparison of two IRS methods, nothing more. It does not apply the ordering rules in Publication 587 line by line, does not handle daycare use, and does not account for state conformity. Confirm your figures with IRS Publication 587, the instructions for Form 8829, or a licensed tax professional before filing.
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