Sub test()
Dim TabData() As Variant
With ActiveSheet
fin = .Range("AV" & .Rows.Count).End(xlUp).Row
TabData = .Range("A1:AW" & fin).Value
For i = LBound(TabData, 1) + 1 To UBound(TabData, 1)
TabData(i, 49) = TabData(i, 12) * TabData(i, 47) / TabData(i, 7)
Next i
.Range("A2:AW" & fin) = TabData
End With
End Sub