I often compare Ireland and Indiana when it comes to relative size, population, and the fact that roads tend to lead towards a large population hub kind of in the center.

IN pop = 6.8 mill
Island of Ireland pop = 7 mill (5.1 + 1.9)

IN area = 36418 square miles
Island of Ireland area = 32596 square miles

Dublin area pop - 1.256 mill
Indianapolis area pop - 2.075 mill