=SUM([cells])/COUNT([cells]

But even there you may run into limits.

Alternatively, why don't you sum up a few groups of the cells, say 5 groups
of 50, sum those 5 sums together and divide by 250?

Dave
--
Brevity is the soul of wit.


"Tom Young" wrote:

I'm trying to average the values in approximately 250 non-adjacent cells
(there is no pattern to the cell location).

My first obstacle was the 30 argument limit, which I hoped to get around by
using =AVERAGE (()). In another thread someone referred to this as using
"multiple area ranges."

That seemed to be working fine until about one hour into the tedious process
of selecting cells while holding down ctrl, I get the "too many characters"
notification.

Surely there is some efficient way of averaging more than 30 non-adjacent
cells?? I can't believe that Excel makes it this difficult to do a simple
calculation. Any suggestions? Thanks.