Home office deduction calculator
There are two ways to work it out, and you can pick whichever is worth more each year. Here they are side by side, from the same three answers.
Both methods
The simplified method is $5 a square foot, up to 300 square feet, so $1,500 at most. The regular method is the office’s share of the home, by area, times what the home costs to run.
My office is square feet of a square foot home, which costs a year in rent or mortgage interest, utilities, insurance and repairs.
a year comes off your profit with the regular method. That is $2,164 back at your rate.
If you own, the regular method also takes depreciation on the office’s share of the house, so it is usually worth more than shown here.
Who can take it
The space has to be used regularly and only for the business. A desk in the corner of a bedroom can count if nothing else happens at it; the kitchen table can’t.
It also has to be your principal place of business, which it is if you do the business’s admin there and have no other fixed place to do it, or a place you meet clients. A separate structure like a studio in the garden only needs the first rule.
It is for the self-employed. Employees can’t deduct a home office on their federal return, even when they work from home every day.
What goes in the regular method
Rent, or mortgage interest and property tax if you own. Utilities, homeowner’s or renter’s insurance, general repairs, security and HOA dues. Owners also take depreciation on the office’s share of the house, but not the land.
Repairs to the office itself, like painting it, count in full. A phone line and internet are deducted on their own, not here. How internet works.
Before you choose
Can I switch methods?
Yes, from one year to the next. The regular method needs Form 8829 and records of what the home cost; the simplified one needs only the area.
What if the business made little this year?
Neither method can take more than the business earned after its other expenses. Under the regular method what is left over carries to next year; under the simplified method it is lost.
I own my home. What happens when I sell?
Depreciation you took, or could have taken, under the regular method is taxed when you sell, at up to 25%. The simplified method has no depreciation, so nothing to pay back.
Does the simplified method lose my mortgage interest?
No. If you itemize, the mortgage interest and property tax still go on Schedule A in full. Under the regular method the office’s share moves to the business instead.
Checked on September 25, 2026 against Publication 587, Business Use of Your Home and Instructions for Form 8829. An estimate for your records, not tax advice.
More for the self-employed
See it on every receipt.
Reimburse works out both methods from your answers, keeps the better one, and writes the home office in on the first of every month.