Prevent formula calculation from overriding validation

[CindyMc]

I have a list of 4 numbers with a sum at the bottom. One of the 4 numbers is
a calculation, the others are direct entry. The calculated number cannot be
less than zero. How do I fix this so it doesn't allow this when the number
is calculated?

 

[T. Valko]

The calculated number cannot be less than zero.

You should have posted the formula.

Try changing your current formula to something like this:

=MAX(0,your_current_formula_here)

 

[Luke M]

Select the three cells that create the sum. (I'll assume B1:B3). Under Data -
Validation, choose custom rule. Input the following:
=SUM($B$1:$B$3)>=0

Note that if a user simply selects a cell however and presses "delete" a
negative sum is still possible.