Sorry. Maybe my question wasn't clear.

What I'm trying to do is between cell A1 and A3, you can put a maximum of
100 only.

Ie - If cell A1 is 10 and A2 is 50. Then the maximum I can enter in cell A3
is 40
If cell A2 is 50 and cell A3 is 20 then I can only enter max of 30

Regards,


"Bernie Deitrick" wrote:

Kim,

Select cell A3, the use Data / Validation... choose "Custom" and use the formula

=AND(A3=0,A3<=(100-A1-A2))

HTH,
Bernie
MS Excel MVP


"Kim" wrote in message
...
Can someone please help me with the problem below. I need a formula where I
can set a limit of figure I can input in a cell.

Example:

A B C D E
1 50
2 20
3

I want to set cell A1 to A3 that the total input cannot be more than 100. If
i enter 50 on A1 and 20 in A2 and in cell A3, they can only enter between 0 -
30.

Thanks.