You suject line mentions "sum if functions" but your explanation suggests
otherwise.

I need to calculate Z5 - X5

I take that to mean: Z5 minus X5

If that's what you want try this:

=IF(Z5=0,"",Z5-X5)


--
Biff
Microsoft Excel MVP


"Scott R" wrote in message
...
Sorry to do this as i think its a very basic formula its just i dont use
them
often..

I need to calculate Z5 - X5 but not if Z5 is blank (or zero). Any help
would
be great or where exactly i should look as ive tried a few different
formulas
from excel help but theyre not working..