Use an IF statement (and possibly an OR to handle if either are empty

=IF(OR(A1="",A2=""),0,A1-A2)

--
HTH
Nick Hodge
Microsoft MVP - Excel
Southampton, England
DTHIS
web: www.nickhodge.co.uk




"JSR929" wrote in message
...
Ok, I'm going crazy here! I know I've done this before years ago but for
the
life of me can't figure it out. Ok, lets see if I can explain this clearly
enough so you can understand...

Lets say in Cell A1 I have the number 180. In cell A2 there is nothing. In
cell A3 I have this Formula =A1-A2. After making that formula, in cell A3
appears 180. I want cell A3 to reflect 0 until I put a number in cell A2
to
subtract.

Here's what we're doing... in our office, we are having our own
competition
as to who can lose the most weight/percentage of weight in 8 weeks. I have
a
spreadsheet to track all the changes, however, the 180 is the starting
weight
and in cell A2 is the following weeks weight. A3 is the difference,
however
in A3, it still displays 180 until I actually put in a new weight in A2.

Does anyone know how to have A3 reflect "0" until it can subtract A1 & A2?

Thanks!!!