How do I set up a formula to count only unique items in a column?

For Example: If I have a column with 8 items but two are duplicates. I want
the formula to return a value of only the unique items (6)

ABC
DEF
GHI
JKL
MNO
PQR
ABC
DEF

Thanks Jennifer

it worked great

Lyle


"jennifer" wrote:

> I take no credit; Not my creation:
>
> =SUMPRODUCT((A1:A30<>"")/COUNTIF(A1:A30,A1:A30&""))
> or
> =SUMPRODUCT(--(A1:A30<>""),1/COUNTIF(A1:A30,A1:A30&""))
>
> "LYLERR" wrote:
>
> > For Example: If I have a column with 8 items but two are duplicates. I want
> > the formula to return a value of only the unique items (6)
> >
> > ABC
> > DEF
> > GHI
> > JKL
> > MNO
> > PQR
> > ABC
> > DEF