Dim MyFile As String = "~/photos/mymug.gif"
Dim finfo As New FileInfo(Server.MapPath(MyFile))
Dim FileInBytes As Long = finfo.Length
Dim FileInKB As Long = finfo.Length / 1024
Response.Write("File Size: " & FileInBytes.ToString() & " bytes (" & FileInKB.ToString() & " KB)")