Conditional calculations across sheets isn't easy. Try this:

=SUMPRODUCT(SUMIF(INDIRECT("'7-"&ROW(INDIRECT("1:31"))&"'!N:N"),"0"))/SUMPRODUCT(COUNTIF(INDIRECT("'7-"&ROW(INDIRECT("1:31"))&"'!N:N"),"0"))

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Biff
Microsoft Excel MVP


"JimG" wrote in message
...
I have an AVERAGE IF formula that works fine on a single worksheet for July
1st...
=AVERAGEIF('7-1'!N:N,"0",'7-1'!N:N)

I need it to work across 31 worksheets, so it will accurately calculate
the
averages for all values greater than zero, and for the entire month.

Any ideas?