How big is the universe compared to a grain of sand?

How big is the universe compared to a grain of sand? If our Milky Way galaxy, which is around 125,000ly across was to be shrunken down to a grain of sand, the observable universe would be roughly 372 meters (1220 feet) wide, not too bad.

If our Milky Way galaxy, which is around 125,000ly across was to be shrunken down to a grain of sand, the observable universe would be roughly 372 meters (1220 feet) wide, not too bad.