Count unique records

[benjennings]

Hi,

I have 2 columns of information where one column lists site names, the other lists the month. One site name can appear several times during the same month.

I would like a formula that counts the number of unique site names that appear per month.

Any help is much appreciated.

Many thanks,

Ben

 

[Aladin Akyurek]

Hi,

I have 2 columns of information where one column lists site names, the other lists the month. One site name can appear several times during the same month.

I would like a formula that counts the number of unique site names that appear per month.

Any help is much appreciated.

Many thanks,

Ben

Control+shift+enter, not just enter:

=SUM(IF(FREQUENCY(IF($A$2:$A$25<>"",IF($B$2:$B$25="Jan",
   MATCH("~"&$A$2:$A$25,$A$2:$A$25&"",0))),
    ROW($A$2:$A$25)-ROW($A$2)+1),1))

where A2:A25 houses site names and B2:B25 months (month names).