This should do it if you mean "if the cell value is blank, even if the blank
is the result of a formula in the cell"
If Cells(.Row,8).Value="" Then Cells(.Row, 8).FormulaR1C1 =
"=IF(ISBLANK(RC[-3]),0,IF(RC[-3]=""FT"",R10C25*8,R10C25*4))"

This should do it if you mean that both the value of the cell is blank AND
there is no formula within the cell:
If Cells(.Row,8).Formula = "" Then Cells(.Row, 8).FormulaR1C1 =
"=IF(ISBLANK(RC[-3]),0,IF(RC[-3]=""FT"",R10C25*8,R10C25*4))"

--
- K Dales


"Steph" wrote:

Hello, given the worksheet change event code below:

Private Sub Worksheet_Change(ByVal Target As Range)
Application.ScreenUpdating = False
With Target
If .Column = 6 And .Row 11 And .Row < 112 Then
Application.EnableEvents = False
If .Value = "S" Then
Cells(.Row, 8).FormulaR1C1 =
"=IF(ISBLANK(RC[-3]),0,IF(RC[-3]=""FT"",R10C25*8,R10C25*4))"
Cells(.Row, 9).FormulaR1C1 = "=RC[-2]*RC[-1]"
End If
Application.EnableEvents = True
End If
End With
End Sub

How can I have the code NOT put a formula in, for exmple, Cells(.Row,8) if
that call is NOT blank? I only want the formula to be entered if the cell
is blank. Thanks for your help!