Macro to count to last row

Hi there

I have one Macro that i have sorted to count up to the last fill cell it seems to work correct but it is a simple sum up the totals macro see below.
The RISE FALL REDUCED LEVELS Macro has different formulae in each cell so i am wondering how i can get this to also count up to the last fill cell

Sub CALCULATE_AND_PANIC()
lastRow = Cells(Rows.Count, 3).End(xlUp).Row
Range("G5").Formula = "=sum(C12:C" & lastRow & ")"
Range("G7").Formula = "=sum(D12" & lastRow & ")"
Range("G6").Formula = "=sum(E12:E" & lastRow & ")"
End Sub

Sub RISE_FALL_REDUCED_LEVELS()
Range("F13:F26").Formula = "=C12-E13"
Range("G12").Formula = "=G3"
Range("G3").Formula = "16.121"
Range("G13:G26").Formula = "=G12+F13"
End Sub



Any help would be appreciated
Cheers

Mat