One way:

=SUMPRODUCT((A5:A100<"")/COUNTIF(A5:A100,A5:A100&""))

If there are no empty cells within the range then you can reduce that to:

=SUMPRODUCT(1/COUNTIF(A5:A100,A5:A100))

--
Biff
Microsoft Excel MVP


"Karen" wrote in message
...
I have a range of cells (A5:A100). In some cells there are duplicate part
numbers. I want to count ONLY the unique values and not the duplicates.
Does
anyone know how this can be done and what formula I would use to
accomplish
this?
Thank you very much in advance, Karen