EXCEL: How to sum many cells/ values corresponding to another “merged” cell?

Question

Hello :)

I have a similar table to the attached picture. I want to sum the total cost for every project and add these values in the column "total cost" without doing it manually, because my database is really huge.

Could anyone help me in this regard?

Answer 1

Put this in C2 and copy down:

=IF(OR(A3<>"",B3 = ""),SUM($B$2:B2)-SUM($C$1:C1),"")

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If you want it on the first line then:

=IF(A2<>"",SUM(B2:B$104000)-SUM(C3:C$104000),"")

In C2 and copy down.

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If you want it in everyrow:

=IF(A2<>"",SUM(B2:B$104000)-SUMIF(A3:A$104000,"<>",C3:C$104000),C1)

In C2 and copy down.

Answer 2

This sounds very much like the "Data", "SubTotals" feature. Did you try this already?