SUMIFS Alternative

[Simon1185]

Morning guys,

I've been looking for an alternative to SUMIFS as I have a sheet I need backwardly compatible with Excel 2003. I've looked at SUMPRODUCT which I understand is a good alternative to COUNTIFS but does not allow for summing. I've now moved on to looking at an array formula I picked up from an internet search, but it's not working properly for me. The crux of my Excel 2007 formula is:

=SUMIFS(Estimates!H:H,Estimates!A:A,A2,Estimates!P:P,"")

The array formula suggested would seem to tranlate as follows:

=SUM(IF((Estimates!A2:A1000=A2)*(Estimates!P2:P1000=""),Estimates!H1:H1000,0))

However all this is doing is summing the whole H:H range, regardless of the conditions. (note, I've only shortened the range of cell in the array formula as the place I found it noted that including a whole colmun would slow the sheet to a crawl).

Any ideas? Many thanks in advance.

Simon.