=SUMPRODUCT((A1:A20<"")/COUNTIF(A1:A20,A1:A20&""))

--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Jason30" wrote in message
...
HOw do I count the number of unique cells whilst excluding those which
have
identical values? I.e.

Col A

1234
1234
3456
4567

The number of unique numbers is 4 (as the first 2 are the same)