How to calculate variance in Pivot table between two columns? (Beginner in Power Pivot)

Hi All,

Please see the attached sample for reference.

I have a data set where I need to calulcate the variance of sales between two months in a pivot table. This is a recurring activity and that's why I am loooking for help.

Note:
The Sales calculated for each chain under June and July are calculated through values field as a sum in the field list.
In the field list : Column = Sales Month
Row = Chain group
Value = sum of sales for each chain
I have tried the caluclated field option in the pivot analyze tab, but no luck. I am a beginner in Power Pivot and I am looking for a solution so that I can learn and implement.

Thank you so much

Hi alansidman,

Sorry for the delay in responding back, I was away due to health reasons.

Yes I what I have shared is the Pivot table. I will share the data file here shortly.

Thnak you so much!