Home office expense percentage for both partner

[ubuntu]

Me and my wife both use 10% respectively (20% in total) of our home as home office. 
I am confused whether we put 10% or 20%  in this section "percentage (%) of home being used for personal purposes"  for our individual file 

[Geo123]

Hello ubuntu,

Indicate the percentage (%) Of your home that is used for personal, non-business relate purposes. 
= 100 -c 
To calculate the percentage of work-space-in-the-home expenses you can deduct, use a reasonable basis, such as the 
area of the work space divided by the total finished area (including hallways, bathrooms, kitchens, etc.). 

If you are working in a designated room 
Since the room is used only for work, the percentage Of your home used as a work space is also the percentage Of your 
work space used for employment purposes. 
A = Size of work space (designated room or shared area) 
B = Total finished area of home 
C = Percentage of your home that you used as a work space (rounded two decimal places) 
C AE x 100 

If you are working in a common (shared) area 
You need to calculate the percentage of the work space that was used for employment purposes by providing the 
numbers of hours worked in that space within a calendar week (7 days or 168 hours). 
D = Number of hours (hours worked in a work week) 
E = 168 hours 
F=D/E 
C = Percentage of your home that you used as a work space (rounded two decimal places) 
C = A/B x F x 100