Hi Drew

If they are numerical values in the cells, then you don't really need the

error traps.

If any values are 0, then you may end up with a zero result, but none of the

formulae shown are divisions, hence there will not be a #DIV/0 error

You could use

=IF(I5="","",IF(COUNT(C11,F3,I5)<3,"",C11-(F3*I5)))

Since none of the formulae are really complex, then you could simply use

=IF(I5="","",IF(ISERROR(C11-(F3*I5)),"",C11-(F3*I5)))

EDATE is available in XL2003, provided you have the Analysis Toolpak

installed, Tools>Addins>Analysis Toolpak.