Where do I indicate the square feet of the room that I rent out through air bnb?

[jtax]

Not sure that you do. What makes you think you do? You might need to allocate expenses to your rental/non-rental part and one way to do that might be by square feet. But I think you do that outside of TT and either enter a % if TT allows will split it up for you (I don't know that it does). If not you will have to a little bit of your own spreadsheet work and calculate the numbers to enter based on % yourself.

Here is a previous question about reporting airbnb income. I don't know about the Schedule C vs E issue but you will find discussion of that and further links below.

https://ttlc.intuit.com/community/investments-and-rental-properties/discussion/i-rent-one-of-the-roo...

[Carl]

Sounds to me like you are renting out a room in your primary residence, and you didn't check the box for "I rent out a part of my primary residence". When that box is checked, later screens will ask you for total sq ft of your residence, then the sq ft of the area you rent out that is exclusive to the renter. With that information, the program will then figure what percentage of your allowed expenses can be claimed on the SCH E.