Calculate the sum of numbers in a row of a Pivot table and display the value in a single field

[estellocrypto]

I have a problem with a pivot table in Qlik Sense. I can't share the data so I recreated the problem in a table:

In Qlik Sense, this is a pivot table. The light green fields are calculated by multiplying the quantity with the price and the dark green are the two light green fields added together.

What I need now is a formula that sums up all the values in the dark green row, so that in this case the result would be 50. I want to display that value in a KPI field. Is there any way I can do that in Qlik Sense?

I tried to calculate the sum of the total but it doesn't give me any result. I tried to activate the "Total" option, it doesn't display the right values at all.

Thank you for your help! 

[marcus_sommer]

Your example doesn't provide any information about the data-model or the expressions in the pivot but by a "classical" data-structure something like the following should work within a KPI:

sum(aggr(sum(Price*Quantity), Product, Month))

- Marcus