I rent out 1 room in my 4 bedroom house that I also live in. How would I split expenses

[ccdworak]

I rent out 1 bedroom and personally live in another room of my 4 bedroom house. The whole house is 1700. The rented room is 110 sq ft. and mine is 280 sq ft. All the other rooms in the house are shared spaces between me and my roommate. When figuring out rental property square footage, would the square footage of the rented property be 1420 sq ft. (House sq ft total minus my room) or would it be 110 sq ft. (Size of my roommates bedroom)

[MinhT]

The shared space should be allocated between rental use and personal use. You'll need to make an estimate of how to divide up the common space between the 2 uses. That allocation will be added to the area of the rented room to obtain total rental space, and then the percentage of rental use.