Worksheet_Change multiple ranges and different formulas

[Paul_Hossler]

Meantime, just guessing at a format and data, you could try something like this

It's not as elegant as it could be

Option Explicit


Private Sub Worksheet_Change(ByVal Target As Range)
    
    Dim cFactor As Double
    
    cFactor = Range("C1").Value
    
    Application.EnableEvents = False    '   <<<<<<<<<<<<<<<<<<<< Important
    
    With Target.Cells(1, 1)
        
        Select Case .Column
            Case 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25
                If Len(.Value) = 0 Then
                    .Offset(0, 1).ClearContents
                Else
                    .Offset(0, 1).Value = .Value / cFactor * 100#
                End If
            
            Case 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26
                If Len(.Value) = 0 Then
                    .Offset(0, -1).ClearContents
                Else
                    .Offset(0, -1).Value = .Value * cFactor / 100#
                End If
            Case Else
            
        End Select
    End With


    Application.EnableEvents = True


End Sub