counting the total, grouped by a specific field

[Obi1]

Hello,

I've got a table with the following columns:
FirJrPer: which shows what company, year and month the data is about (text).
Car: the licenceplate of the specific car
Departement: text
Nrcars: indicates how much that car was used by that departement (0-1).
Totalcost: total cost of the cars for that specific period and company.

My problem: I want a calculated column, which gives me, for each row (=car), the sum of Nrcars for the rows in the table where FirJrPer is the same.
I've tried it with:
=sumx(filter('Cars',Cars[FirJrper]=Cars[FirJrper]),Cars[Nrcars]),
hoping that the filter-expression would give the selection I want, but it gives me the whole table. If I replace it with a specific example, e.g. =sumx(filter('Cars',Cars[FirJrper]="LNU20111",Cars[Nrcars]), then I get the correct result. So, I want the same thing, but with "LNU20111" being what is in the FirJrper-field of the particular row.

Hope someone can help.

Steven

[Richard Buttrey]

Hi Steven,

Probably a Pivot Table?
Any chance you could upload the workbook - anonymised if necessary with a few notes referring to your data and examples of the results you expect.

Regards

[Obi1]

Hello Richard,

I've enclosed a screenshot. Maybe that'll make it more clear.

I want the calculated column, where you see 16 everywhere, (which is the total for LNUYT20111), to give the total, grouped by FirJrPer.
Right now, I'm finding a solution by making first a pivot that gives the number I want, and then import it in powerpivot, link with it, ...
But it seems to me there should be an easier way.

Steven