From a space.com article about the size of the observable universe:

“All the pieces add up to 78 billion-light-years. The light has not traveled
that far, but “the starting point of a photon reaching us today after
travelling for 13.7 billion years is now 78 billion light-years away,”
Cornish said. That would be the radius of the universe, and twice that
– 156 billion light-years — is the diameter. That’s based on a view
going 90 percent of the way back in time, so it might be slightly
larger.“

What’s also amazing, is that if you wrote the number googolplex, (1^googlol = 1^1^100) in one point font, it wouldn’t fit _in_ the observable universe.

That’s pretty badass.

Image [cc] selected at coincidence from [flickr]