That's a little over 1/4th the diameter of Pluto.
Irma is 313,087 Shaquille O'Neals from head to toe. (Or… 341,169 Charles Barkleys.)
Irma is wider than every state except for Alaska, Montana, and Texas.
It's bigger than Olympus Mons, the largest mountain in our solar system.
It would take the world's fastest marathoner 32 hours to run from one side to the other.
A sprinting cheetah could do it in 5.6 hours.
420 miles is 7 times the thickness of the Earth's atmosphere.
Irma is 20 miles wider than when Hurricane Katrina made landfalll.