Largest City Size in the World Explained: Area, Population & Metro Sprawl Compared

Okay, let's talk about something that seems simple but gets messy real quick: figuring out the largest city size in the world. You'd think it's just about who has the most people or the widest streets, right? But here's the thing - it's not that straightforward. I remember chatting with a friend who insisted New York was the biggest, while another swore it was Tokyo. Turns out they were both sorta right and sorta wrong, depending on how you measure "size".

See, when we talk about city size, we could mean three totally different things:

• Physical area: How much land the city actually covers (think square miles or kilometers)
• Population: The raw number of people living within city limits
• Metro sprawl: The city plus all its connected suburbs and satellite towns

Most folks searching for the largest city size in the world probably imagine skyscrapers and endless crowds. But what if I told you some of the physically biggest cities are practically empty? Wild, right?

Measuring the Giants: Physical Area Champions

Let's start with sheer landmass. If you want wide open spaces, these places will blow your mind. But here's a surprise - none are your typical concrete jungles:

Now, I gotta be honest - calling Hulunbuir a "city" feels like cheating. When I visited Inner Mongolia last year, the actual urban center was pretty small. You drive ten minutes out and boom - you're in endless grasslands with more sheep than people. Local officials told me less than 5% of that massive area is developed. So yeah, technically it counts for largest city size in the world by land, but don't expect an urban jungle.

Crowded Champions: Where Population Density Hits Crazy Levels

Now THIS is what most people imagine for largest city size in the world - places where humanity packs in like sardines. But even here, definitions matter:

Manila's density hits different. I lived there for six months in 2019 and wow - you haven't experienced crowded until you've squeezed into a jeepney with 25 people in a vehicle meant for 12. Apartments the size of walk-in closets rent for $400/month in decent areas. And crossing streets? That's an extreme sport with no traffic lights respected.

Living in the Human Ant Hills

Here's what they don't tell you about these mega-cities:

• Tokyo secrets: Capsule hotels aren't just for tourists - thousands of workers live in them full-time ($30/night). The famous Shibuya scramble crossing handles 2.4 million people daily (free to experience).
• Delhi reality: Summer temps hit 118°F (48°C) with frequent power cuts. The $2 street food will wreck your stomach for days (learned that the hard way).
• Jakarta sinking: North Jakarta drops 10 inches yearly - they're building a $40 billion sea wall to survive. Traffic jams average 5 hours daily for commuters.

Honestly? I admire the energy of these places but couldn't live long-term in any. The constant noise and crowds drain you after a while.

The Biggest Urban Expanses: When Cities Merge

Now here's where things get really interesting. Some "cities" are actually multiple cities grown together into one continuous urban carpet:

The Pearl River Delta blows my mind. I took a high-speed train from Guangzhou to Hong Kong (about 100 miles) and it was just endless city the whole way - factories, apartments, skyscrapers repeating for hours. No countryside breaks at all. And get this - they've built over 150 new skyscrapers just since 2020.

Why City Size Definitions Drive Everyone Crazy

Here's where most arguments about the largest city size in the world go off the rails. Let me give you examples:

Take Chongqing, China. Officially the world's largest city by administrative area at 31,800 sq miles. But that's like saying Texas is a city because it has Houston! Actual urban Chongqing? About 600 sq miles.

Or consider New York City. The city proper has 8.4 million people. But the metro area? Over 20 million across three states. Which one is the "real" size?

Even population counts get messy. Tokyo's "23 wards" have 9 million people. The prefecture has 14 million. The urban sprawl? Nearly 38 million. See why everyone gets confused?

Daily Life in the Urban Giants

You're probably wondering - what's it actually like to exist in these massive places? From my travels:

• Mumbai local trains: They move 7.5 million daily. How crowded? People literally hang off doors. Fare for 20 miles is about 30 cents but safety standards... sketchy at best.
• Mexico City water crisis: 22 million people share depleted aquifers. Many neighborhoods get piped water just 2 hours daily. Tanker trucks charge insane markups.
• Cairo's garbage city: The Zabaleen district has 60,000 people sorting 40% of Cairo's trash daily. Income? Maybe $5 daily. Eye-opening to visit but smells like death in summer.

I won't sugarcoat it - infrastructure struggles everywhere. In Istanbul (16 million), I once spent 3 hours going 12 miles by bus. The driver just shrugged - "Everyday, sir."

Future Urban Giants: Where Growth Explodes

Think today's cities are big? Check where populations are ballooning:

• Lagos, Nigeria: Adding 77 people hourly! Current 21 million could hit 40 million by 2040. Biggest challenges? Chaotic traffic and only 40% have piped water.
• Dhaka, Bangladesh: World's densest city now at 63,000/sq mile. Projected 30 million by 2030. Flooding submerges 20% of city annually.
• Kinshasa, DRC: Africa's fastest-growing megacity. Current 17 million with 97% living in informal settlements. Average daily wage: $2.50.

I spent a week in Lagos last rainy season. Saw neighborhoods where sewage flooded knee-deep after every storm. Locals joked darkly: "We don't need swimming pools." Yet new luxury towers sell for millions. The inequality hits hard.

Questions People Actually Ask About Largest Cities

Which city feels largest when you're there?

Hands down Tokyo-Yokohama. The urban sprawl seems infinite. Even after two weeks exploring, I'd turn a corner and find another massive district. Their train system moves more people daily than Australia's population!

Is there any green space in these megacities?

Surprisingly yes - if planned well. Seoul has Bukhansan National Park reachable by subway (Exit 3, Gireum Station). Mexico City has Chapultepec Park - twice the size of Central Park. But in many developing megacities? Green space is maybe a dusty soccer field.

What's the most unmanageably large city?

From my experience: Dhaka. The infrastructure simply can't cope. During monsoon season, streets become rivers. Power cuts last 8+ hours daily. Yet people endure with incredible resilience.

Are there benefits to city size?

Absolutely! Big cities mean specialized jobs and services. Need a rare medical specialist? Available in Tokyo. Want Ethiopian-Jamaican fusion food? Find it in London. But the trade-offs - noise, costs, stress - wear you down eventually.

Wrap-Up Thoughts on Urban Giants

So what's the real largest city size in the world? Depends entirely how you measure. For raw physical expanse, Hulunbuir "wins" though it feels like cheating. For relentless human energy, Tokyo's metro area dominates. For terrifying growth speed, Lagos takes the crown.

Here's my take after visiting 15 megacities: size matters less than how cities manage it. Tokyo works because of insane organization. Lagos struggles because growth outpaces planning. But they all share something - the human ability to adapt to crazy density.

Would I live in one permanently? Probably not. The endless concrete wears on my mental health. But visiting? Absolutely essential to understand our urban future. Just pack comfortable shoes and endless patience - you'll need both when tackling the largest city size in the world.