Formeln in Werte umwandeln in einer Megadatei

Sub ChangeCellValues()
Dim Row As Integer, Col As Integer
Dim iRow As Integer, iCol As Integer
'Set iRow entsprechend der Reihenanzahl
iRow = 19500
'Set iCol entsprechend der Columnanzahl
iCol = 60
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
Range("A1").Select
For Col = 1 To iCol
For Row = 1 To iRow
ActiveSheet.Cells(Row, Col).Value = Cells(Row, Col).Value
Selection.Copy
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Next Row
Next Col
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
End Sub