There Are More Doors Than Wheels—Here’s Why
There are more doors than wheels in the world. Here’s why.
Written by R.E. Fulton
Reviewed by Kathleen Flear
From house and apartment doors to cupboard doors, office doors, and doggy doors, there are at least 33 billion doors in the world—meaning that there must be more doors than wheels.
On March 5, 2022, New Zealander Ryan Nixon asked the fateful question on
Twitter
: “do you think there are more doors or wheels in the world?” Like so many great questions, it’s caused a lot of confusion and started a lot of arguments. But finding a definitive answer gets hard quickly. Today,
car insurance
comparison app Jerry
is here with the correct answer. Based on an exhaustive analysis, we’re here to make the case that there are more doors in the world than wheels. Compare insurance quotes from 50+ insurance companies with Jerry in under 45 seconds
Compare insurance quotes from 50+ insurance companies with Jerry in under 45 seconds
4.7/5 rating on the App Store | Trusted by 5+ million customers and 7 million cars4.7/5 app rating | Trusted by 5M+ driversWhat counts as a door?
With a question as complicated as this one, it’s smart to start with some definitions. You probably have a picture in your head of what a “door” looks like, but what actually counts as a door for the purposes of this problem?
The New Oxford American Dictionary has a nice, practical definition: a door is any “hinged, sliding, or revolving barrier” at the entrance to:
- A building
- A room
- A vehicle
- A cupboard
In other words, we’re not just talking about the door to your house—we also have to take into account interior doors, car doors, and, yes, the doors on all the trucks, trains, airplanes, cabinets, and cupboards in the world. Add it all together, and we’ll quickly see that the total number of doors is astronomical.
On the other hand, a doorway doesn’t necessarily count as a door, and neither do drawers,
trunk hatches
, or pictures of doors. To be fair, we’ll rule those out of our calculations. How many doors are there in the world?
If the efforts of mathematicians, Twitter users, and statisticians in the last couple of weeks are any indication, it’s pretty much impossible to accurately count every single door in the world. However, we can use statistics to make some general estimates—and the numbers are pretty astonishing.
Houses
Experts estimate that there are roughly 2 billion houses in the world, with between two and four doors per house, on average. That’s 4 billion doors at a minimum if we only consider a front door and a back door.
Most houses, however, have more than two doors. Factor in a door for every bedroom and one for every bathroom, along with garage doors, basement doors, and even crawl-space doors, and that number grows dramatically.
And let’s not forget the outliers—houses with more doors than the average single-family home. The
Winchester Mystery House
of San Jose
, California, for instance, boasts 2,000 doors in a home with just 160 rooms. The Palace of Versailles
in France, the home base of the “Sun King” Louis XIV in the 17th century, has 2,300 rooms—and, presumably, a door for each! Apartment buildings
What about apartment buildings? According to Statista, approximately 27.63 million households rented apartment units in the United States in 2021. Call that two doors per apartment (again, a low estimate), and we’re looking at a minimum of 55 million apartment doors in the United States alone.
But again, we have to look at the biggest apartment buildings in the world to understand just how many doors multi-unit dwellings add to the world total. Here’s how many units you’ll find in some of the world’s biggest apartment complexes:
- Le Lignon (Switzerland): 2,780 units
- Edificio Copan (Brazil): 1,160 units and 72 businesses
- Sillon de Bretagne (France): 781 units
- Ponte City (South Africa): 464 units
Let’s estimate two doors to each unit: one front door and one bathroom door. That’s certainly a low estimate, but that’s already 10,604 doors to add to the world’s total.
Then there’s the biggest of the big. The Burj Khalifa in Dubai is a 2,722-foot skyscraper that holds the title of the tallest building in the world—and it’s got so many doors that no one’s been able to give an exact count. With 900 residences, 37 floors of corporate suites, 304 hotel rooms, 57 elevators, eight “dining experiences,” and dozens of observation decks, pools, and other amenities, the Burj Khalifa contains over 17,000 doors.
Vehicles
Vehicles are the main place where the world’s wheels seem to outnumber the doors, but a little simple math shows that the transportation sector is more or less a wash.
Car doors became standard around 1923, and the majority of the cars on the road today have four doors and four wheels. On
coupes
, eighteen-wheelers, and other unique vehicles, wheels outnumber doors, but they’re less common than the four-door sedans and SUVs that make up the majority of vehicles in the world. Trains generally have four sets of wheels on every coach, but those eight wheels are typically balanced out by exterior doors as well as the doors that move between coaches. The same goes for airplanes, where entrance doors, emergency exits, service doors, and bathroom doors add up to roughly as many doors as wheels. (And if we count baggage compartment doors, it’s a clear win for doors.)
Cupboards, cabinets, and closets
Take a look around your home. Just how many cupboards do you have? From kitchen cabinets to bathrooms cupboards, the doors add up fast.
Experts estimate that the standard American kitchen has about 12 cabinets. Most homes also have at least one bathroom cupboard, either above or below the sink. What about closets? Add at least one closet for every house and apartment, and we can raise our estimates for house and apartment doors to about 14 doors in addition to the front and back doors we estimated earlier.
MORE: How to install a closet organizer
The final count
Let’s go back to our 2-billion-house estimate. If we multiply that by 16 instead of two, we’ve got a low-ball estimate of 32 billion doors in houses worldwide. What about apartments? Because apartments tend to be smaller than houses, we’ll estimate an average of just ten cupboard and closet doors per apartment—which adds up to 331.56 million doors in apartments in the US alone.
But homes and the doors within are just the beginning. What about the doors in stores, restaurants, and hotels? What about museums and office buildings? And let’s not forget Home Depot—a building with doors that sells more doors inside.
A full count of the world’s doors would also include pet doors, dollhouse doors, stage doors, barn doors, shower doors, church doors, and revolving doors.
The bottom line? There are far too many doors in the world to count, but with easily close to 33 billion doors, they surely outnumber wheels.
Why does it matter?
Sure, the doors vs. wheels debate is a fun time-waster (and a great way to start fights with your friends). But contemplating the number of doors and wheels in the world is also an opportunity to contemplate what’s most important in your life—and the answer you gravitate toward might say something about you.
If your first instinct when you heard the question was “there are more doors in the world,” you might be a more grounded person who looks for stability. After all, doors are most associated with homes. And as our calculations have shown, doors are an essential part of the world’s built environment—the basic structures, from home to work to play, where our lives take place.
Doors are passages to new possibilities, but they’re also practical and stable. And there are far, far more of them in the world than wheels.
Protect your doors and wheels with savings from Jerry
No matter which side of the debate you fall on, you can save money on insurance for the doors and wheels in your life with help from
Jerry
, the trusted car insurance comparison app
. Here’s how. Jerry helps users find the lowest available rates on car, home, and renters insurance. Just enter your information, wait about 45 seconds, and you could get customized quotes drawn from a pool of 50+ top providers. Find a lower rate in the app, and you could reduce the premium you pay to cover your car doors, your cupboard doors, and the doors to whatever home you have.
“Jerrywas wonderful! I used it for my auto and renters policies. I trusted it so much that I signed up my homeowners insurance under Jerry as well. All of the agents are amazingly nice and knowledgeable.” —Mary Y.
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