It's 4 not 3.

=SUM(--(FREQUENCY(IF(B1:B11="X911",MATCH(A1:A11,A1:A11,0) ),ROW(INDIRECT("1:"&ROWS(A1:A11))))0))

which is an array formula, it should be committed with Ctrl-Shift-Enter, not
just Enter.
Excel will automatically enclose the formula in braces (curly brackets), do
not try to do this manually.
When editing the formula, it must again be array-entered.

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HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)



"Amber" wrote in message
...
My data contains 2 columns of data

I want to count column A if column B has not already been counted.
A B
1951 X911
2614 X911
2618 X911
2614 X911
1031 X911
2614 X911
2614 WAT
2614 WAT
2614 WAT
2614 WAT
2614 WAT

In other words, I want to see how many different lines of X911. The
answer
I want is 3 because there are 3 different numbers associated with X911

HELP!!!!