Thanks Steve. Unfortunately the result is not the correct number when just
averaging the individual invoice numbers. It may be getting skewed by one of
the invoices being listed much more than the others. Thanks for trying.

"Steve Dunn" wrote:

Hi Nadine,

if your invoice numbers are always numeric, use Biff's formula from your
previous post.

If they include characters that are not numeric you will need something
like:

=AVERAGE(IF(FREQUENCY(MATCH($A$2:$A$100,$A$2:$A$10 0,0),MATCH($A$2:$A$100,$A$2:$A$100,0)),$B$2:$B$100 ))

HTH
Steve D.



"Nadine" wrote in message
...
I posted this question with the title of Average If which was a misleading
title.

I have a column of invoice numbers and multiple rows of data pertaining to
each one. So one invoice number could have 10 rows of data pertaining to
it
so the invoice number will be repeated 10 times. Then on each line is the
time it took to receive the data so this number will be the same on all 10
lines. I have hundreds of rows of data but only a handful of invoice
numbers. I need to find the average of the days based on the unique count
of
the invoice numbers. I already have my formula for the unique count but
now
need one for the average when the invoice numbers are not in contiguous
cells
down the column.

Example:
Col A Col B
Invoice # # Days
12345 11
12345 11
12345 11
98995 15
66438 37
12345 11
98995 15
12345 11

So there are 3 unique invoice numbers. How do I write the formula to find
the average number days it took to receive all three? I'm in Excel 2003.