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Home Office Deduction Calculator

Estimate the simplified deduction and the business share of selected home expenses. The actual-expense figure is a starting point for Form 8829—not a completed tax deduction.

No signup · Calculations stay in your browser · Reviewed September 20, 2026

For a qualifying self-employed home business with a fixed office area in one home. Generally, the space must meet regular and exclusive use and business-location requirements. This model does not cover daycare, inventory-storage exceptions, moving homes, changing office area or multiple businesses.

Space and qualifying period

Use a consistent area measurement for home and office.
Count a month only if it has at least 15 days of qualifying use; fixed office size is assumed.
Income attributable to this qualified home business minus business expenses unrelated to the home. Enter 0 if there is no remaining income.

Actual expenses for the qualifying period

Enter only expenses incurred during that period—not a full year if you used the office for only part of the year. Do not include mortgage principal or capital improvements.

Interest potentially eligible under applicable tax limits.
Actual tax treatment and limitations require Form 8829 and Schedule A.
Indirect repairs only. Do not include repairs to unrelated areas or capital improvements.
Direct expenses are added in full, not multiplied by the home-use percentage.

Read the two results differently

The simplified estimate applies $5 to up to 300 square feet, averaged over 12 months, then applies the entered income limit. A 200-square-foot office used for six qualifying months gives $500 before the income limit.

The actual-expense allocation multiplies shared entered costs by office area ÷ home area and adds eligible office-only expenses. It does not apply all deduction ordering rules, depreciation, carryovers, casualty losses or Schedule A interactions. Do not copy this allocation onto a tax return or choose a method solely because it is larger.

Why not name a winning method?

Homeowners can have deductible interest and taxes treated differently from operating costs. A single blanket income cap on all actual expenses can be wrong. We show the components for further review instead of claiming a precise allowable deduction without the required facts.

Regular employees generally cannot deduct unreimbursed home-office costs under these self-employed rules; special classifications need separate review. A deduction reduces taxable income—it is not a dollar-for-dollar tax refund.

For business structure planning, see the LLC versus S-Corp employment-tax comparison.

Sources and review

Calculation rules checked September 20, 2026. These tools are educational estimates, not personal financial or tax advice.

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