At 10 people per square meter, that means we can fit 1,000 people in a 10-by-10-meter square. 54,000 people can fit in an American football field, and 26 million people – about the population of Scandinavia – can fit into one square mile, Urban writes. Central Park, which is 1.3 square miles or 3.4 square kilometers, could hold the population of Australia or Saudi Arabia. All 320 million Americans could huddle together into a square that is 3.5 miles or 5.7 kilometers on each side.

And what if we found a piece of land for everyone on Earth – all 7.3 billion of the world’s people? Urban calculates that we would need a square that is 27 km, or 16.8 miles, on each side – an area smaller than Bahrain and, yes, New York City.

Urban calculates that we could fit 590 million people in Manhattan — that takes care of North America. We could fit 1.38 billion people in Brooklyn, equivalent to the population of Africa, South America and Oceania. Queens could hold 2.83 billion — roughly the equivalent of India + China + Japan. 1.09 billion could fit in the Bronx, taking care of Europe, while 1.51 billion could fit Staten Island, making room for the rest of Asia ex-China, Japan and India.