Home Office Deduction Calculator

What the home office number means

When cash is tight, a possible deduction can feel like money already coming back. It is not. A home office deduction reduces qualifying business income; it is not a credit and does not reimburse the cost dollar for dollar. This calculator compares two planning estimates for a self-employed person: the IRS simplified option and a broad actual-expense allocation. It does not decide whether the space qualifies.

The regular-and-exclusive-use rule matters before any arithmetic. A dining table used by the family usually fails exclusivity even if client work happens there every morning. Exceptions exist for certain storage and daycare use. Read IRS Publication 587, Business Use of Your Home before putting the result on a return.

How the 2026 comparison is calculated

The IRS simplified option uses $5 per square foot for up to 300 square feet, a maximum of $1,500 before the income limitation. That safe-harbor amount is not newly indexed each year; this page labels it 2026 because that is the return year being planned.

For the actual estimate, office square feet are divided by total home square feet. That percentage is multiplied by the whole-home expenses entered, then direct office-only expenses are added. Actual Form 8829 ordering is more detailed: direct and indirect expenses, casualty losses, otherwise-deductible mortgage interest and taxes, depreciation, prior carryovers, and the gross income limit do not all behave identically. Use this result to decide whether the record-heavy method deserves a full 2026 Form 8829 calculation.

Rates current as of September 2026.

Fully worked 2026 example

Suppose a freelance designer uses 150 square feet of a 1,200-square-foot apartment only for work. Business use is 150 ÷ 1,200 = 12.5%. Annual rent, utilities, renter's insurance, and eligible whole-home costs entered total $24,000. A $500 repair applies only to the office. Business profit available before the home office deduction is $50,000.

The simplified estimate is 150 × $5 = $750. The actual estimate is $24,000 × 12.5% + $500 = $3,500. Both fit under the entered $50,000 income limit, so the calculator leads with the $3,500 actual-expense estimate. That does not mean every dollar entered belongs on Form 8829. The designer must classify the costs, retain proof, and confirm eligibility.

Mistakes that make the result look safer than it is

• Counting shared space as exclusive business space can invalidate the premise.
• Entering the home's full cost and also entering one of those same costs as direct counts it twice.
• Treating furniture, equipment, or internet as an indirect home cost can mix deductions governed by different rules.
• Forgetting the business-income limit can turn a large theoretical amount into a smaller current deduction; actual-method carryover treatment needs the form.
• Ignoring depreciation because it is inconvenient can make an actual-method homeowner comparison incomplete and can hide later recapture consequences.

What to do next

Measure the dedicated space and save a photo or floor plan. Separate direct office costs from costs for the whole home. Renters should keep leases and payment records; homeowners should collect basis, land value, mortgage-interest, property-tax, insurance, repair, and placed-in-service records. Run the official form both ways before filing. If the actual method wins only slightly, weigh the extra records and depreciation consequences rather than automatically choosing the larger screen number.

Disclaimer: General information only, not tax or legal advice. Verify eligibility and the final 2026 calculation with IRS instructions or a qualified tax professional.