I have a 1.7mb spreadsheet I have inherited, with a large area (60 columns by
230 rows) of similar nested IF statements. I have tweked part of one of the
IFs to sum the cells to the left (sum($v10:v10) etc) and the file sixe has
doubled to 3.4mb.

I have done the usual checks for hidden areas, etc and simplified the
formula, but it remains at 3.4mb. If I remove the sum part of the nested IFs
and put in a single cell reference, then the size drops down to 1.7mb, so I
know that is what is causing the problem. In case it matters, the formula is
currently:

=ROUND(IF(OR(W$7<"To
Pay",W$5<$H10),0,-SUM($G10,$V10:V10)/MAX(1,$J10-W$5+1)),2)

The file is used in around 100 different models, so I do not want to make
all the versions so much larger. Any suggestions, or am I just stuck with it?