Home Office Deduction Calculator — Simplified Method
This free home office deduction calculator (simplified method) estimates your IRS home office deduction two ways: the simplified method at $5 per square foot (capped at 300 sq ft, or $1,500), and the regular method as a percentage of your actual home expenses. Enter your numbers below — everything recalculates instantly as you type.
Enter your numbers
The part of your home used regularly and exclusively for business.
Needed for the regular-method business-use percentage estimate.
Rent or mortgage interest, utilities, insurance, repairs — the expenses the regular method allocates. Not used by the simplified method.
Your top federal income-tax bracket — used only to estimate the tax savings a deduction produces.
Your results
| Office area counted (simplified) | 150 sq ft × $5/sq ft |
|---|---|
| Business-use percentage (estimate) | 10.00% |
| Annual home expenses (estimate) | $24,000.00 |
| Method with the larger deduction | Regular method |
| Estimated tax savings at your rate | $528.00 |
Simplified method follows the IRS rate of $5/sq ft up to 300 sq ft ($1,500 max). The regular method is an estimate only — it allocates your entered home expenses by business-use percentage and ignores depreciation, carryover limits, and recordkeeping details. Not tax advice. Confirm your deduction with a CPA or tax professional.
How to use this calculator
Enter your home office area — the part of your home you use regularly and exclusively for business. The simplified method multiplies it by $5 per square foot, up to 300 sq ft, so you will see your deduction update instantly.
For the regular-method comparison, add your total home area and monthly home expenses (rent or mortgage interest, utilities, insurance, repairs). The calculator converts those into a business-use percentage and an estimated annual deduction. Your marginal tax rate turns the bigger of the two deductions into an estimated tax savings figure.
How it works
The simplified method is the exact IRS formula: deduction = min(office sq ft, 300) × $5. A 150 sq ft office gives 150 × $5 = $750. A 400 sq ft office is capped at 300 sq ft, so the deduction maxes out at $1,500. No expense tracking, no depreciation recapture, and no Form 8829 — you claim it directly on Schedule C.
The regular method is an estimate: business-use % = office sq ft ÷ total home sq ft, then deduction ≈ business-use % × annual home expenses. For example, a 150 sq ft office in a 1,500 sq ft home is 10%, and with $2,000 of monthly home expenses: 0.10 × $2,000 × 12 = $2,400 per year (estimate). Real filings also allocate depreciation, allow only certain expenses, and are limited by your business income — none of which this estimate models.
Estimated tax savings is simply the larger deduction multiplied by your marginal tax rate: $2,400 × 22% = $528 (estimate). That is the approximate income-tax value of the deduction, not your refund, and it is labeled an estimate because your real bracket, other deductions, and eligibility rules will differ. Nothing on this page is tax advice.
Frequently asked questions
What is the simplified method for the home office deduction?
The IRS simplified method lets you deduct $5 per square foot of your home office, up to 300 square feet, for a maximum deduction of $1,500. You do not have to track individual home expenses or file Form 8829 — you claim it directly on Schedule C.
What is the maximum home office deduction under the simplified method?
$1,500. The IRS caps the simplified method at 300 square feet, and 300 × $5 = $1,500. Any office space above 300 square feet gets you nothing extra under the simplified method, which is one reason larger home offices may do better with the regular method.
How does the regular method for the home office deduction work?
The regular method applies your business-use percentage (office square feet divided by total home square feet) to your actual home expenses — mortgage interest or rent, utilities, insurance, repairs, and depreciation. It usually produces a bigger deduction than the simplified method, but it requires receipts, records, and Form 8829.
Can I switch between the simplified and regular methods each year?
Yes. The IRS lets you choose either method for any tax year, regardless of which one you used before. Many people use the simplified method in low-expense years and the regular method when their actual home costs make it worthwhile — enter your numbers above to compare both side by side.
Do I have to be self-employed to claim the home office deduction?
The simplified home office deduction is for self-employed people who use part of their home regularly and exclusively for business. Employees generally cannot claim it for tax years 2018 through 2025, when the unreimbursed employee business expense deduction was suspended. Rules for later years may differ — confirm with a tax professional.