Let's assume the first 6 months of data are on Sheet1 in the range A1:A100.
The second 6 months of data will be in the same range on Sheet2.

On Sheet2 in some cell enter this formula (just don't enter the formula in
the range A1:A100):

=AVERAGE(Sheet1!A1:A100,A1:A100)

--
Biff
Microsoft Excel MVP


"Arayne" wrote in message
...
I have split up my worksheet so the first 6 mos is on one sheet and the
last
6 months is on a second sheet. I need to bring over my YTD Average and
continue to be able to have the YTD Average update automatically as I
enter
data each day. How do I do this?