If you just want the cell formatted, try

Format/Cells/Custom
#" ft²"

The superscript 2 is created by holding down the Alt key and typing 0178 on
the number keypad (not from the number row above the keyboard).



" wrote:

It just occured to me that a really nice feature of Excel would be to
keep track of units if you wanted it to. It is part way there with
the CONVERT() function, but what I would envision would be to be able
formate a cell as a special kind of number that has units associated
with it. So when you take 2 cells with ft as units that it knows the
the resulting value has units of feet squared.