Home Office Deduction Worksheet (Excel + Google Sheets, simplified vs regular method)

There are two ways to deduct a home office, and the bigger one depends on your numbers. The simplified method is $5 per square foot, up to 300 square feet. The regular method (Form 8829) gives you your office's share of rent or mortgage interest, real estate taxes, insurance, utilities and repairs, plus depreciation if you own. This worksheet works out both from the same inputs and tells you which one is bigger.

What's inside

Settings: office and home square feet, months used, business income and other expenses, and for owners the home's basis and the month the office was first used

Expense log for up to 500 bills: date, category and amount, with checks for missing fields and bills from another year. Or just type yearly totals

Side-by-side comparison: simplified deduction, regular deduction in Form 8829 order (mortgage interest and taxes, then operating expenses, then depreciation), the better method and the difference

Income limit and carryovers: if your business income is too low, it shows what's allowed this year and the operating expense and depreciation carryovers to next year (Form 8829 lines 43 and 44)

Depreciation: 39-year schedule with the mid-month first-year rates from IRS Publication 587, prorated for months used

Works in Excel and Google Sheets. Comes as a blank file and a copy filled with an example, plus a PDF guide

Example (the sample file): a 200 sq ft office in a 1,600 sq ft owned home, used all year. Simplified method: $1,000. Regular method with $9,400 mortgage interest, $5,400 real estate taxes, $4,920 of insurance, utilities and repairs, $350 to paint the office and a $320,000 home basis: $3,840.60. Same rules as our free home office deduction calculator.

Sources: IRS Publication 587, Form 8829 and its instructions, Rev. Proc. 2013-13 and the IRS simplified option page (checked October 20, 2026). The office must be used regularly and only for business.

Not affiliated with the IRS. Not tax advice.