How big is New York City?
Up to 8.24 mil by 2013, actually. By contrast, the entire U.S. has 311.59 million. That single city has over 2.6% of the nation's population. Doesn't seem like much, but think about how many cities are in the U.S. total.
468 square miles
Population: 8.1 million
5 counties, but we call them boroughs
really really really big
population: 8.1 million/ 468 square miles