COLUMNWIDTH

Returns the column width of the active cell.
For instructions on how to add a function to a workbook refer to the page under Inserting Functions

'iColumnNo - The column number you want the width of

Public Function COLUMNWIDTH(Optional ByVal iColumnNo As Integer = -1) As Single 

   If iColumnNo = -1 Then 
      COLUMNWIDTH = ActiveCell.ColumnWidth 
   Else 
      COLUMNWIDTH = ActiveSheet.Columns(iColumnNo & ":" & iColumnNo).ColumnWidth 
   End If 
End Function