Honestly, if you ask someone to name the biggest city in the world, they’ll usually blurt out Tokyo or New York. Maybe Shanghai if they’re feeling fancy. But they’re basically always talking about people—the literal wall-to-wall human beings.
If we’re talking about biggest cities by size—as in, how much actual dirt and rock the city limits cover—the list gets weird. Really weird. You end up looking at places in the middle of the Arctic or the Australian Outback that have more caribou or kangaroos than actual tax-paying citizens.
The Technical Trap: What Does "Size" Even Mean?
Before we get into the heavy hitters, we have to settle a beef. There are three ways to measure a city, and geographers argue about this constantly.
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First, you’ve got the City Proper. This is the legal boundary. If you cross a certain line on a highway and the "Welcome to..." sign appears, you're in the city proper.
Then there’s the Urban Area. This ignores the legal lines and just looks at where the buildings stop. It's the "concrete footprint."
Finally, there’s the Metropolitan Area. This is the giant sprawl of suburbs and commuter towns.
If you look at the biggest cities by size using the "City Proper" metric, the winners aren't megacities. They're administrative anomalies.
Greenland is Secretly Winning the Space Race
The actual, undisputed heavyweight champion of land area is Sermersooq, Greenland.
It’s not a city in the way you’re thinking. There are no subways. There are no Starbucks on every corner. But legally? It’s a municipality that functions as a city. It covers roughly 531,900 square kilometers.
To put that in perspective, you could fit the entire country of France inside this "city" and still have room for a few smaller European nations.
It’s got a population of about 24,000 people. That’s it. You have thousands of miles of ice and rock for every single human being living there. If you’re looking for a place to get away from your neighbors, this is the one.
The China Factor: Cities the Size of Countries
China does things differently. In the 90s, they started a trend of reclassifying entire regions as "cities" to streamline how they managed them.
The most famous—and confusing—example is Chongqing.
You’ll often see Chongqing listed as the "biggest city in the world" with a population of over 32 million. But if you actually visit, you’ll find that the vast majority of that "city" is actually farmland and rugged mountains.
The municipal boundary of Chongqing covers 82,403 square kilometers. That’s roughly the size of Austria.
Why China "Fakes" the Size
- Administrative Ease: It's easier to run a province if you just call it a city and put one mayor in charge.
- Economic Stats: Massive boundaries make for massive GDP numbers, which looks great on a spreadsheet.
- Infrastructure: It allows the government to build high-speed rail and highways between "districts" that are actually hundreds of miles apart.
Other Chinese giants like Nagqu and Hulunbuir are even bigger in terms of land. Nagqu covers over 450,000 square kilometers. It’s basically a chunk of the Tibetan Plateau with a city name slapped on it.
The American Sprawl: Where the Concrete Actually Is
If you hate the "empty ice" and "mountainous province" definitions and want to know which cities have the most actual built-up land, the leaderboard changes completely. This is where the United States dominates.
New York City (the metropolitan area) is a monster. When you count the continuous urban sprawl that leaks into New Jersey and Connecticut, it covers about 12,093 square kilometers.
It’s a different kind of "big." It’s not empty space; it’s a solid carpet of asphalt, steel, and suburban lawns.
The Sprawl Kings
- New York-Newark: The king of the urban footprint.
- Boston-Providence: A massive "megalopolis" that basically connects multiple states.
- Atlanta: Famous for its low-density sprawl. It’s huge because everyone wants a big yard and a three-car garage.
- Chicago: A grid that just keeps going until it hits the cornfields of the Midwest.
Mount Isa: Australia’s Hidden Giant
There’s a town in Queensland, Australia, called Mount Isa. For a long time, it held the Guinness World Record for the largest city by area.
It covers about 43,310 square kilometers.
Why? Because it’s a mining town. The city limits were drawn to include the massive mining leases and the surrounding outback to ensure the local government could tax the resources. If you drive from one side of "the city" to the other, you’re looking at a multi-hour road trip through a desert.
The "Real" Answer Depends on Your Goal
If you’re a traveler, knowing that Sermersooq is the biggest city doesn't help you much unless you really like glaciers.
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If you're looking for the biggest cities by size because you want to explore a never-ending urban jungle, you go to Tokyo-Yokohama or New York.
But if you want to see the weirdness of human geography, you look at the administrative giants. It’s a reminder that "City" is just a word we use for a box on a map. Sometimes that box contains 30 million people, and sometimes it just contains a whole lot of snow.
How to Use This Info
- Check the "Urban Extent": When booking travel, look at the urban area, not the city proper. If you stay in "Chongqing," you might end up in a village three hours away from the skyscrapers.
- Population Density Matters: A big city with low density (like Atlanta) requires a car. A smaller city with high density (like Paris) is walkable.
- Verify the Map: Always look at satellite views before assuming a "large" city is actually a "metropolis."
The next time someone tries to tell you which city is the largest, ask them if they’re counting the people or the dirt. It’s never the same answer.
Next Steps for Your Research
- Compare Population Density: Look up the "inhabitants per square kilometer" for New York vs. Chongqing to see the difference between "sprawl" and "crowding."
- Explore Google Earth: Zoom into the borders of Mount Isa or Sermersooq to see how much of that "city" is actually inhabited.
- Analyze Urban Corridors: Research the "BosWash" megalopolis to see how multiple big cities are merging into one giant continuous size-beast.