=SUMPRODUCT((FREQUENCY(A1:A10,A1:A10)0)*1)

Returns 2 with your sample data.


Gord Dibben MS Excel MVP

On Thu, 17 Sep 2009 11:52:19 -0700, mrsmasterg
wrote:

I have a spreadsheet in which duplicate data appears multiple times in
groups. I would like to count each occurence. Ex.
12345
12345
12345
12345
78912
78912
78912
78912
78912

expected result is that each occurence is counted once.
12345 occurs once
78912 occurs once

I do not want to use a pivot table because each 'group' has multiple rows of
data that needs to be shown.