I rented a room to a roommate (170 days) and lived in it myself as well. (200 days) The system doesn't allow a sum higher than 366 although we were living there simultan

[PaulaM]

Think of the room (or part of room if this is your case) as separate unit. Enter in TurboTax as rental and under the Property Profile, indicate that you rented a part of your home on the page, Do Any of These Situations Apply to This Property? 

On the page, Was This Property Rented for All of 2016?, Answer 'no' if your rental unit was not rented all year and enter the rental use days and the personal use days for that unit.

Note:  The personal use days means did you use the rental unit personally after it was placed in service. If the room was rented for 170 days, then you could not have had access to it for 170 days. Personal use then would be 196 days.

[Alpacino]

What happens if both bedrooms are equal size, and the roommate has 100% access to the rest of the house and all utilities are included.  They are not renting a room, they are sharing the home 50%/50%.  The homeowner lived in the house 365 days and rented not just a room but 100% of the home to them.  It won't allow the homeowner to put 365 and rent of "x" number of days.  Then it will look as though only the bedroom was rented, which is untrue.

[Carl]

For the space y ou rented out to the renter, that space was "exlusive to the renter". I seriously doubt you used that space that was exclusive to the renter, for your personal use during the time it was exclusive to the renter.

Days rented is the number of days it was exclusive to the renter.

Days of personal use is the number of days you used that exclusive space for *your* personal use. More than likely, that will be ZERO days of personal use.