http://www.hocexcel.online/vba-tim-dong-cuoi-cung-chua-du-lieu-trong-excel.html

gistfile2.bas

Sub LastColumnInOneRow()
'Find the last used column in a Row: row 1 in this example
    Dim LastCol As Integer
    With ActiveSheet
        LastCol = .Cells(1, .Columns.Count).End(xlToLeft).Column
    End With
    MsgBox LastCol
End Sub