Struggling with a variance/difference column in table visual

[SamfarUK]

I have three tables whereby i have an actual percentage and a target percentage. I want a final column to show me the difference between the actual percentage and the target percentage. I am not having much luck. Can someone please help?

Here is a snippet of my report :

You can see the measure I have built for the difference. 

[amitchandak]

@SamfarUK , If Both % are measure, you measure should be like

[M1] - [M2]

If they are not then calculate a measure like below using base columns

Divide(Sum(A), Sum(B) )  - Divide(Sum(A1), Sum(B1) ) 

[SamfarUK]

Thanks for your response.

If using the first table as an example, Overweight [%] is a measure but Target is not. 

I am relatively new to Power BI and still learning; I don't quite understand what your base column solution is. If you wouldn't mind elaborating on this process. 

Thanks,

Sam