Print File Size

The following function allows you to print the file size, given the number of bytes, which is obtained from the FileInfo.Length property. The function always print the size in 2 decimal digits and will automatically determine the correct layman unit label.

Public Shared Function PrintFileSize(ByVal size As Long) As String
    Dim unit As String
    Dim d As Double

    Select Case size
        Case Is < 1024
            d = size
            unit = "B"
        Case Is < 1048576 '~1K
            d = System.Math.Round(size / 1024, 2)
            unit = "KB"
        Case Is < 1073741824 '~1MB
            d = System.Math.Round(size / 1048576, 2)
            unit = "MB"
        Case Is < 1099511627776 '~1GB
            d = System.Math.Round(size / 1073741824, 2)
            unit = "GB"
        Case Else
            d = System.Math.Round(size / 1099511627776, 2)
            unit = "TB"
    End Select

    Return d.ToString("0.00") & unit
End Function

The following is the example on printing the file size of notepad.exe.

Dim fi As New System.IO.FileInfo("C:\Windows\notepad.exe")
MessageBox.Show(PrintFileSize(fi.Length))