Since one cell can't change another cell's formatting, this will require
an Event macro.

Put this in your worksheet code module (right-click on the worksheet tab
and choose "View Code")"


Private Sub Worksheet_Change(ByVal Target As Excel.Range)
With Target(1)
If .Address(False, False) = "A1" Then
If IsEmpty(.Value) Then
Range("A3").NumberFormat = "General"
Else
Range("A3").NumberFormat = "0%"
End If
End If
End With
End Sub





In article <ECE08CF5-8C3E-4F46-BEA4-E7F8F7DA2186@microsoft.com>,
Qaspec <Qaspec@discussions.microsoft.com> wrote:

> I'd like the number format for the value in cell a3 to be a general number if
> a1 is empty and i'd like the format to be a percentage if a1 contains a
> value.
>
>