Eg Column A =IF(ISBLANK(Fix!A7),"",Fix!A7)
Is this a problem?

Yes, it is. Suggest you change it all to return a zero instead of "" (which
is text), viz.:
=IF(ISBLANK(Fix!A7),0,Fix!A7)

Then you could use the simple:
=SUMPRODUCT((C1:C800=0)*(D1:D800=0)*(A1:A800-B1:B8000))
to get the result
--
Max
Singapore
http://savefile.com/projects/236895
Downloads: 15,500, Files: 352, Subscribers: 53
xdemechanik
---
"andrew" wrote:
Hi Max,
It worked on my test file BUT on the actual file (which extends the rows to
800), it doesn't seem to be working.

I realised that the cells in reference has formulas within them (all four
columns per below). Eg Column A =IF(ISBLANK(Fix!A7),"",Fix!A7)

Is this a problem?