All of the following INPUT fields have a size of 14:
Since the INPUT field in test 5 is using monospace font, it should fit exactly 14 characters (eg. the visible string should be "12345678901234", no more, no less).
However, when an INPUT field uses a proportional font - as tests 2-4 do - the specified number of visible characters is always an average, not an accurate value. Try filling the field with lowercase 'l' letters or uppercase 'W':s to get the point.