As self empl., to get the home office deduct, y do I deduct 100% of my other expenses and not the % of those expenses from the home office since I only use a % of income?

[Critter-3]

Where to enter :  

Where do I enter the home office deduction for my business?

Understanding the form 8829 and the meaning of direct and indirect expenses : 

Home Office Expenses … Business Use of the Home

https://www.irs.gov/businesses/small-businesses-self-employed/home-office-deduction

[VolvoGirl]

Yes.  You deduct 100% of your other self employment expenses.  And Home Office is a % of your total house size, not % of income.