Excel 2007 : Counting number of times x appears in a column

Counting rows.xlsx

What formula can I put in Col B?

So that it counts the number of times the item in Col A has appeared.

Data cannot be sorted and preferably not a CPU intensive formula as its going to be put into a 15,000 row spreadsheet

Thanks

In B2 try:

=IF(A2="","",COUNTIF($A$2:A2,A2))

And copy down.

Top Man, cheers for the quick reply!!!