=SUMPRODUCT(--(NOT(ISBLANK(A1:A20))),--(A1:A2020),A1:A20)

or

=SUMPRODUCT(--(A1:A20<""),--(A1:A2020),A1:A20)

--
HTH

Bob Phillips

"Buckeye" wrote in message
...
How does excel recognize a blank cell. I'm using the sumif statement and
want to sum if a cell is blank?

Help!