Show Variance between 2 columns set as % of grand total

[ariana_night]

Hello,

In my matrix, I need to show (in a separate column to the right of the last column) the variance between "Contribution to XS" and "FL % of TTL INV". Contribution to Excess - FL % of TTL INV  is not an option because "Contribution to XS" and "FL % of TTL INV" are the same fields as the first 2 columns you see below [FL INV] and [FL XS INV], but set as % of grand total because that is what I need shown. 

I appreciate any help with this.

[jgeddes · Accepted solution]

The clarification was great, thank you.

I replicated the portion of the data you shared into a table with an index column to get

I then wrote measures for FL XS RATE 

FL XS Rate =

DIVIDE(SUM(FL_INV_TABLE[FL XS INV]),SUM(FL_INV_TABLE[FL INV]))

Contribution to XS

Contribution to XS =

DIVIDE(

    SUM(FL_INV_TABLE[FL XS INV]),

    CALCULATE(SUM(FL_INV_TABLE[FL XS INV]),ALL(FL_INV_TABLE[Index]))

)

FL % of TTL INV

FL % of TTL INV =

DIVIDE(

    SUM(FL_INV_TABLE[FL INV]),

    CALCULATE(SUM(FL_INV_TABLE[FL INV]),ALL(FL_INV_TABLE[Index]))

)

And finally the variance as

Variance =

[Contribution to XS] - [FL % of TTL INV]

I end up with

[jgeddes]

Hello,
I do not fully understand what you are looking for but if you can share the desired results for at least the first couple of rows I may be able to assist.

Cheers.

[ariana_night]

Here's an example in excel (see below): basically =F2-G2 

but it is not that simple in PowerBI desktop, unless I do not think it is. See explanation after screenshot.

The column above "Contribution to XS" is a field called 'Excess Inventory' [FL XS INV] and after renaming it for the visual, I set the field as % of grand total see image below: (same goes for the "FL % of TTL INV" column in the image above). 

I'm not too sure how to create a measure to give me the desired result (shown in column H of first image). 

Please let me know if I am still unclear or need to provide additional information.