entering business use of home expenses for shared workspace

[saktax2019]

I use a room at home for office space (self employed).  The room is not exclusively used for work.  It is used 1 hour/24hr day if I average the hours worked in that room over a year. 

According to the CRA if the room is used exclusively for business, then eligible expenses are based on  (area of room/total home area = 1/10 in my case). 

However if the room is a shared space, the CRA says you have to calculate the number of hours/week the room is used for business purposes  ( in my case:  1/24).   

So the eligible business related expenses are:  (1/10) x (1/24) x expenses.

Question: I have TurboTax Basic and it assumes that the room is exclusively used for business (input only room area/home area).   There is no input for shared space situations where the time that the room is used for business (in my case 1/24) is factored into the calculation. 

Am I missing something here?

[TurboTax_Susan]

To calculate your percentage; take the area or number of rooms you use for business purposes divide by the total area or number of rooms in your home. Multiply that result by the number of hours in the day you use your home for business purposes divided by 24. And then, multiply that result by the number of days you use your home for business purposes divided by 365.

To enter the calculation above, enter 100 in the Total area or rooms in the home. Enter the percentage calculated in the Area or number of rooms, of the workspace.