I tested out your macro and it works as advertised.
Just needs a bit of a tweek. :-)
I believe the OP wanted both formulas entered at the same time.
So the macro would need to enter: =K2+L2
then directly below, enter the: =$M$2
So something like:
Dim Bcell As Range
For Each Bcell In Sheet2.Range("M1", Sheet2.Range("M" & Rows.Count).End(xlUp))
If Bcell.Row > 1 Then
Bcell.Formula = "=K" & Bcell.Row & "+L" & Bcell.Row
If CDbl((Bcell.Row / 2)) <> Round(Bcell.Row / 2) Then
Bcell.Formula = "=$M$" & Bcell.Row - 1
Also I could only get it to work on Sheet 2 of my workbook.
Is there some way to make it active on the Current Sheet,
not restricted to just sheet 2?