Home Office Deduction Calculator

The home office deduction lets self-employed people write off part of their home costs for the space they use to run their business. There are two ways to calculate it. The simplified method multiplies your dedicated office square footage by a flat IRS rate of $5.00 per square foot (2026), capped at 300 square feet — a maximum deduction of $1,500. The actual-expense method multiplies your business-use percentage by your real home costs. The calculator above estimates both. (Source: IRS, Simplified Option for Home Office Deduction, and Publication 587.)

This deduction is claimed on Schedule C by self-employed people, freelancers, and single-member LLC owners. W-2 employees generally cannot claim it federally. Whichever method you pick, the numbers here are educational — estimates, confirm with your tax professional.

Simplified method vs actual-expense method

The simplified method is a flat-rate shortcut: $5.00 per square foot of dedicated office space, up to 300 square feet, for a maximum of $1,500. No receipts, no depreciation math — just measure the room. The actual-expense method takes your business-use percentage and applies it to real home costs (rent or mortgage interest, utilities, insurance, repairs, and depreciation). It usually produces a larger deduction, but it asks you to track and total those costs across the year. (Source: IRS Pub 587.)

Estimates — confirm with your tax professional.

What qualifies as a home office

To claim either method, the space has to pass the IRS "regular and exclusive use" test and generally be your principal place of business. "Regular" means you use it consistently for business, not once in a while. "Exclusive" is the strict part that trips most people up: the space must be used only for business. A desk in the corner of a bedroom can qualify if that defined area is used solely for work — but a kitchen table where the family also eats, or a spare room that doubles as a guest room, does not. (Source: IRS Publication 587.)

"Principal place of business" generally means the home is where you conduct the bulk of your work, or where you handle administrative and management tasks (billing, scheduling, bookkeeping) if you have no other fixed location for them. There are limited exceptions — for example, a separate free-standing structure used for business. When in doubt, the exclusive-use rule is the one to get right. Estimates — confirm with your tax professional.

How to calculate business-use percentage

Under the actual-expense method, your business-use percentage is how much of your home the office takes up. The most common way to figure it:

Worked example. Say your home office is 150 sq ft and your whole home is 1,500 sq ft. Your business-use percentage is 150 ÷ 1,500 = 10%. If your eligible home costs for the year (rent, utilities, insurance, repairs, depreciation) total $24,000, your actual-expense deduction is 10% × $24,000 = $2,400. Compare that to the simplified method on the same office: 150 sq ft × $5.00 = $750. In this case the actual method is worth roughly three times as much — which is exactly why it pays to capture your home costs.

If your rooms are roughly equal in size, you can instead use a room-count method — one office out of five comparable rooms is 20%. Use whichever reasonable method best reflects your space. Estimates — confirm with your tax professional.

One important limit: the home office deduction generally cannot create or increase a business loss (a gross-income limitation applies). If your deduction would push your business into the red, part of it may be carried forward instead. (Source: IRS Pub 587.)

Which method should you choose?

Here's a simple rule of thumb:

• Small office and no appetite for receipts? Use the simplified method. It's fast, needs zero documentation of costs, and gets you up to $1,500 with a tape measure.
• Larger office or high home costs? Run both and take the bigger legitimate number. The actual method has no fixed cap, so a sizeable office or expensive home often makes it the winner.

The catch is that the actual method only rewards you if you actually have the home costs captured — utility bills, insurance, repairs, and the rest, totaled for the year. That's tedious to reconstruct in April, and missing receipts quietly shrink the deduction. This is where spend capture matters: ExpenseBot pulls receipts and bills straight from your Gmail and uploads, categorizes them, and keeps running totals in a Google Sheet — so when you run the actual-expense numbers, the home costs are already there.

You can also switch methods year to year, so it's worth re-running both each tax season. Estimates — confirm with your tax professional.

Frequently Asked Questions