What Is the World’s Largest City?

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The definition of a city varies, but it's generally thought to be an inhabited place that's more populous than a town or village. The size of that population can range from several thousand to tens of millions. And if we're talking about the world's largest city as it relates to population, we need to look to Japan.

What's the World's Most Populous City?

According to the UN's World Cities Report for 2018, Tokyo is the largest city on Earth, with a population of more than 37 million occupying the metro area. For comparison, there are fewer people living in the entire state of Texas (about 28.6 million) or on the entire continent of Australia (approximately 25.5 million). The population residing within Tokyo's official city limits is smaller at 14 million, though that's still impressive. The Japanese capital saw its first population dip in a quarter of a century during the COVID-19 pandemic, but it hasn't lost its No.1 spot on the list.

The next most populous urban area is Delhi, India, which was home to around 31.1 million residents in 2018. Though it's America's biggest city, New York doesn't come close to the top of the ranking. The population in 2021 stood at about 8.46 million within the city borders and 19.77 million for the greater metro area.

What's the World's Biggest City in Square Miles?

New York may be small compared to some Asian cities, but it holds a different international superlative. If your definition of the world's biggest city looks at literal size rather than population, the Big Apple takes the cake. Its square mileage ranges from 3300 to 4700 square miles, depending on what sources you look at. (City borders aren't as black-and-white as a you may think, which makes it tricky to measure both area and total population.)

When discussing the world's largest cities, people usually mean population, not area. If you've ever been to a city where the apartments—and the commuters—are stacked on top of one another, you know that physical space can be limited in the planet's busiest metropolises. To see how crowded America's cities can get, here are the most—and least—densely populated cities in the U.S.

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