For this purpose, you definitely want to start at the bottom and work up. That
said, are you SURE this is what you want? If it's just for visual effect (i.e.
spacing), you will have fewer problems with formulas if you just increase the
row height. That said, this macro will insert a new row between each of the
existing rows. I have assumed that your worksheet has 65,536 rows, and the
last used row can be identified by looking at column A.
Sub InsertRows()
Dim r as Long
Application.ScreenUpdating = false
r = Range("A65536").End(xlUp).Row
For r = r To 2 Step - 1
Cells(r, 1).EntireRow.Insert
Next r
Application.ScreenUpdating = True
End Sub
The reason you start from the bottom is that the instant you insert a new row,
the rows below it are renumbered, which makes a royal mess of the For/Next
loop.