The diameter of the universe was incorrectly "reported" to be 156 billion lightyears a few years ago and has been widely circulated around the internet since then. This is explained under size misconceptions
here.
Best current theory has the diameter of the visible universe at 92 billion lightyears (this is slightly smaller than the "observable" universe) with an age of 13.7 billion years.
As Tormod and Sanctus say, it is possible for galaxies and other visible things to be 46 billion lightyears away even if the light has taken nearly 13.7 billion years to reach us because of expansion.
The furthest visible light we can see on earth right now is the cosmic microwave background radiation at 46 billion lightyears distance from us. When that light was emitted it was only 36
million lightyears away from the matter that would eventually become us. It took a great deal of time (13.7 billion years) for that light to travel that relatively short distance because the distance expanded 1,292 times over while the light was traversing.
~modest
