Calculate the difference between the count of 2 GA4 events on an area chart

[smoorthy]

Hi,

I have a stacked area chart that shows the usage trends of two GA4 events with their event count for the past 12 months, with count as Y axis and year-month as x axis. These two events are on the legend. Now I want another parameter(new event) on the graph which is basically the subtraction of these two specfic GA4event counts. I thought this should be as simple as New value = GA4eventcount1 - GA4eventcount2, but when I try the visual calculation it is not as simple. When I try to enter the formula for calculation it doesn't let me select the specific event name counts to subtract. Not sure how to get this new value.

Any help/suggestion is welcome appreciated.

Thank you

[lbendlin]

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[smoorthy]

This is a sample of how the graph looks on Powerbi. I am using GA4 events and their event count for the data. I want a new event/parameter which calculates the difference betwen Photos Clicked and Photos Edited. When I try to do this using Visual calculation, I can't seem to do this.

Sample Data below with Expected Outcome

Event Name	Photos clicked	Photos Edited	Photos clicked - Photos Edited
Month-Year	Event Count	Event count
2024-11	100	90	10
2024-12	300	250	50
2025-1	250	220	30
2025-2	400	380	20