if you have fewer than 30 columns you could use
=max(Max(A:A)-Min(A:A),MAx(B:B)-Min(B:B),...,max(Z:Z)-Min(Z:Z))

if you have more than 30 you could group them
=max((Max(A:A)-Min(A:A,...,Max(Z:Z)-Min(Z:Z)),(Max(AA:AA)-Min(AA:AA,...,Max(AZ:AZ)-Min(AZ:AZ)),(Max(BA:BA)-Min(BA:BA,...,Max(BZ:BZ)-Min(BZ:BZ)))

"bj" wrote:

I think that you would need a macro function to do it in one cell.


"Jerry W. Lewis" wrote:

I have an nxm rectangular range of cells, for which I want to determine the
largest columnwise data span ("range" in statistical terms). Clearly, I can
do this using a row of m helper cells each containing
=MAX(column)-MIN(column)
with the desired result then given as =MAX(helper_row).

Can this be done in a single cell without the helper row?

Jerry