Using DEC2BIN() with large numbers

Question

I\'m trying to convert 4503599627370495 into binary in Excel. DEC2BIN() returns #NUM! error because DEC2BIN cannot handle such a large number.

Any thou

Answer 1

I needed a VBA function to convert Excel decimal integers to binary since MS failed me, yet again. I came up with the following, but I had to accept a string of ones & zeros as output, which was OK for me. It uses log base 2 which may be unique (or not?) and works for all positive integers as-is.

Function Dec_Bin(dx As Integer) As String
    Dim x As Integer
    Dim y As Long
    Dim z As Integer
    Dim zz As Double
    Dim ch As String
    Dim str As String, s1 As String
    Dim lead As Boolean

    ch = String(15, "0")
'    Stop
    zz = Log(dx) / Log(2)
    z = Fix(zz)
    y = dx - 2 ^ z
    z = 15 - z
    Mid(ch, z, 1) = "1"
    While y > 0
        zz = Log(y) / Log(2)
        z = Fix(zz)
        y = y - 2 ^ z
        z = 15 - z
        Mid(ch, z, 1) = "1"
        Wend

    ch = ch & "B"
    Dec_Bin = ch
End Function