Hi Debbie,
Try the following entered as an array (Shift-Ctrl-Enter):
=SUM(1/COUNTIF(Range1,Range1))
For example if you have
a
b
a
c
d
e
s
w
a

in column a
then =SUM(1/COUNTIF(A1:A9,A1:A9)) entered as an array will properly return 7


"Debbie t" wrote:

Is there a simple way I can count only one occurence of a text value in a
list where there are several duplicates.
Thanks