Many thanks for all your help - I forgot to say that some of the cells within
the column are blank. Do I need to alter the formula in anyway? I suspect
this maybe why I am having problems.

"Bernard Liengme" wrote:

There is nothing wrong with the formula - it worked on my worksheet
Save you file, reopen and try again
It this fails I suspect a corrupt file
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"SiH23" wrote in message
...
I would be most grateful if someone could offer me some help.

I need to count the number of unique values within a column range. Each
value consists of a series of alpha and numberical characters.

I have used the formula below but it keeps crashing my spreadsheet:

=SUMPRODUCT((1/COUNTIF(A1:A5,A1:A5&"")))

Any help or advice would be greatly appreciated.