hi jt,

=COUNTA(A1:A100)-COUNT(1/FREQUENCY(A2:A100,ROW(INDIRECT("1:"&ROWS(A2:A100)) )))

--
isabelle



Le 2012-04-09 17:27, jt a écrit :
Hi there,
I have a column on numbers and I was wondering if I can add a formula
to the bottom of the column that would tell me how many dublicate
numbers there are.

thanks in advance for your time.