Home Office Deduction Estimator

The IRS simplified home office method allows $5 per square foot of dedicated office space, capped at 300 square feet — a maximum deduction of $1,500 a year regardless of how much larger the space actually is. A 180-square-foot home office comes out to $900.

Square footage beyond 300 doesn't add anything under this method. The actual-expense method exists for home offices where a bigger deduction is worth the extra recordkeeping — worth asking about if the space is large or the home's actual costs are high.