You don't say what to do if both A3 and B3 have a value.

Assuming that one of those cells has to be nil then use the formula B6+B3-A3

cheers,
Rusty

"maud0361" wrote in message
...
Using XP and Excel 2003-how do I create a formula for the following
outcome:
Cell A3 is nil, cell B3 has a value of say $500.00. I want to add cell B3
to
say cell B6 which has a value of say $1000, but if cell A3 has a value and
B3
is nil I want to subtract A3 value from B6.