=SUMPRODUCT((A1:A20=1)/COUNTIF(B1:B20,B1:B20&""))

--

HTH

RP
(remove nothere from the email address if mailing direct)


"carl" wrote in message
...
I have my data like so:

ColA ColB
1 A
1 B
2 A
2 B
1 C
1 D

Is there a way yo count the number of unique values in ColB if ColA value
equals 1.

So in the above, the answer would be 4.

Thank you in advance.