Size of the Universe

Astronomers have made an estimate on the size of the universe.
This is based on examining cosmic background microwave radiation.
156 Billion Light Years in diameter, assuming its spherical.
By comparison, and getting into Carl Sagan mode for a second:
If the distance to the nearest large spiral galaxy, Andromeda (2 MLY away) was the distance across the diagonal of your 19 inch monitor screen, the distance across the known universe would be 24 miles from end to end.