Option Compare Database Option Explicit Function Convert2Bin(n As Long, Optional split As Boolean) As String Dim s As String, position As Long, working As Long, temp As Long ' working = n s = "00000000" ' For position = 7 To 0 Step -1 temp = Int(working / (2 ^ position)) If temp = 1 Then Mid(s, 8 - position, 1) = "1" End If working = working - (2 ^ position) * temp Next position ' If Not IsMissing(split) Then If split = True Then s = Left(s, 4) & " " & Right(s, 4) End If End If Convert2Bin = s End Function