Ethan Siegel, in his "Starts With a Bang" blog has an article about the size of the universe.
Originally Posted By: Ethan Siegel
If the Universe does curve back and close on itself, its radius of curvature is at least 150 times as large as the part that’s observable to us! Meaning that — even without speculative physics like cosmic inflation — we know that the entire Universe extends for at least 14 trillion light years in diameter, including the part that’s unobservable to us today.


That is pretty big. It isn't necessarily infinite, but it is a lot bigger than most historical figures have had.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.