Greater Greater Washington


What if "inside the Beltway" were a city?

If "Inside the Beltway" were a city, how would it compare to other major cities? It would be almost the size of Los Angeles but half as dense a little larger in area than Chicago but less dense than Los Angeles.

Image by Michael Rodriguez. Click for interactive version.

The latest Census data show that Montgomery County reached 1 million people, a statistic that has gotten a lot of worthy attention. Still, let's remember that jurisdiction boundaries are pretty arbitrary. As commenter AlanF also pointed out, DC, Arlington, and Alexandria (the "core jurisdictions") have just about reached 1 million as well (999,662 as of the latest Census estimates).

Michael Rodriguez decided to analyze "inside the Beltway" as if it were its own city. Given the way the Beltway separates communities, it's a good natural boundary and means more than the artificial lines between counties or between DC and Maryland.

Inside-the-Beltway would have about 1.7 million people. in 423 square miles. That's a little smaller than Los Angeles and only about half the density of people per square mile.

Update: Commenter npm points out that Rodriguez's table appears to be incorrect, and "Inside the Beltway's" density may be more like 80% of Los Angeles' rather than 50%.

Table by Michael Rodriguez.

Update 2: A reader with access to GIS systems has estimated the land and water area of "Inside the Beltway." Plugging in those numbers, and assuming that the other numbers on the table are correct, the table would look like this.

Update 3: Rodriguez has updated his post and fixed the errors in the DC and "Inside the Beltway" numbers. I've updated the table to reflect them.

GeographyTotal area
(sq. mi.)
Water area
(sq. mi.)
Land area
(sq. mi.)
(Pop./sq. mi.)
Inside DC Beltway266102561,725,6866,749
District of Columbia68761632,32310,298
New York City4691663028,336,69727,541
Los Angeles503344693,792,6218,087
San Francisco23218547805,23517,177
Click on a column header to sort.

The lower density than Los Angeles comes because most of the land inside the Beltway is actually not very dense, except for central DC, Capitol Hill, along Georgia Avenue, the Rosslyn-Ballston corridor, bits of Silver Spring and College Park, and a few other places.

Density by census tract. Image by Michael Rodriguez. Click for interactive version.

Also, if "inside the Beltway" were a city, metonymy in the national press would be even more severe than it is today.

David Alpert is the Founder and Editor-in-Chief of Greater Greater Washington and Greater Greater Education. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He loves the area which is, in many ways, greater than those others, and wants to see it become even greater. 


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This is such a great thought experiment! Love it!

by Tommy on Mar 19, 2013 10:41 am • linkreport

How is 1.7 M (inside the beltway) anyway close to LA (3.7M)?

Does give you an idea how dense LA really can be, though. DC/Arlington level of density spread in a much larger area.

by charlie on Mar 19, 2013 10:48 am • linkreport

"How is 1.7 M (inside the beltway) anyway close to LA (3.7M)? "

its not, thats the point.

by AWalkerInTheCity on Mar 19, 2013 10:51 am • linkreport

The water area of the District of Columbia was not subtracted from the total area in the calculation of population density as it was for the rest of the geographies. The corrected density should be 10,298 pop./sq.mi.

I think this experiment would be interesting if you compared the DC beltway to other cities of similar land area -- San Antonio, Nashville, Indianapolis, Dallas, San Diego etc.

That lower density than Los Angeles comes because most of the land inside the Beltway is actually not very dense

Also, it comes because Los Angeles is a fairly dense city.

by Scoot on Mar 19, 2013 10:54 am • linkreport

Wouldn't that tiny point at the bottom near the Potomac River actually be outside the Beltway

by kk on Mar 19, 2013 10:54 am • linkreport

This should be a clear message that DC is NOT a dense city at all. If we're not even more dense than sprawling DC, let's build us a bunch of highrises.

by Jasper on Mar 19, 2013 10:55 am • linkreport

Props for use of AP English terminology, "metonymy"

by James on Mar 19, 2013 10:59 am • linkreport

In this case, "size" equals square miles, not residents.

If you look at the chart, you can see that Los Angeles is 503 square miles. Inside-the-Beltway is 439.7 square miles, or "almost the size of Los Angeles."

by Matt Johnson on Mar 19, 2013 11:02 am • linkreport

Cool. This points out some of the silliness on the debate over the height limit in DC, showing that what people really ought to be raising their hands about is the possible densification of the "inside the beltway" area, especially just outside the already dense areas of DC. Key to this would be more development around existing metro stations and more high quality mass transit in the NW, NE and SW -- for example New Hampshire Avenue or up Rhode Island Avenue/Route 1.

by neb on Mar 19, 2013 11:07 am • linkreport

The 440 square miles inside the Beltway seems off. The Beltway is 64 miles, and if it were perfectly circular, the area inside would be 326 square miles [(64/2pi)^2*pi]. Googling, I find a few cites of the "257 square miles" inside the Beltway, which seems more consistent with the 64 mile Beltway.

by npm on Mar 19, 2013 11:08 am • linkreport

Once again, this is why we need streetcars. DC can easily accodomate more density internally with sufficient transportation infrastructure in place.

Also personally I would have just gone with the density map. Using a color gradient for population by census tract produces rather hard to interpret results. Density provides a much cleaner picture.

by Alan B. on Mar 19, 2013 11:10 am • linkreport

The 440 square miles inside the Beltway seems off. The Beltway is 64 miles, and if it were perfectly circular, the area inside would be 326 square miles [(64/2pi)^2*pi]. Googling, I find a few cites of the "257 square miles" inside the Beltway, which seems more consistent with the 64 mile Beltway.


The other easy comparison is the original diamond of the District, which is 10 miles x 10 miles. If the diamond is 100 square miles, there's no way that the remainder (outside the diamond, inside the beltway) is 340 square miles.

by Alex B. on Mar 19, 2013 11:15 am • linkreport

absolutely right on the call for more street cars to promote density rather than rebuilding our downtown for skyscrapers.

by Thayer-d on Mar 19, 2013 11:18 am • linkreport

I agree with npm. Area seems off. DC, Arlington, and Alexandria total 126.7 land area and they make up a very large chunk of inside the beltway. They combine for a pop density of about 8k, so I find it hard to believe that the rest of the area inside the beltway lacks enough density to bring the whole are down to 4k.

Burke has a density of about 5k. I don't believe the entire inside the beltway is less dense than Burke. Places like McLean are at 2,600 per square mile and would be some of the least dense areas inside the beltway.

by jh on Mar 19, 2013 11:19 am • linkreport

I actually had meant to have the density map in there and had already made a screen grab but forgot to include it. I've added it now.

And good point about the numbers. Something felt off to me when I was putting the piece together but I didn't have time to figure out what. I've corrected the post (I think).

by David Alpert on Mar 19, 2013 11:20 am • linkreport

Good catch on the area thing. Assuming 300 is closer the area would be about 6,000 people per sq mile which sounds about right.

by Alan B. on Mar 19, 2013 11:22 am • linkreport

Better question: What if it was a state?

by Miles Grant on Mar 19, 2013 11:32 am • linkreport

Interesting to think what the impact would be on social safety-net issues and anti-poverty policy. As it is, some of the regions wealthiest areas are nicely partitioned off from it's poorest areas.

by oboe on Mar 19, 2013 11:34 am • linkreport

Looks like San Diego would be the best comp in area and population. San Diego is 325.2 square miles and has 1.3M people.

by jh on Mar 19, 2013 11:35 am • linkreport

"its" damnit.

by oboe on Mar 19, 2013 11:36 am • linkreport

Between metonymy and pellucidity, one get's the feeling that DAl's thesaurus has been getting a serious workout lately.

by thump on Mar 19, 2013 11:36 am • linkreport

RE: How big is this area:

I did a quick and dirty using this tool:

The area inside the beltway comes out to 688.2 sq km or 265.7 sq mi. My guess on the reported figure is that someone along the way found the figure out in sq km and multiplied by 0.6 to get sq mi, which is how you would convert linear km to mi.

by MLD on Mar 19, 2013 11:36 am • linkreport

Other, possibly more meaningful, comparisons are to the cities of similar population. Philadelphia, which has slightly less population (>1.5 million people), but within about 1/3rd the area (142.6 m^2); and Houston which has many more people (>2.1 millions) in a much larger area (656.3 m^2).

Those densities are
10519 for Philly
4080 for Beltway DC (barring future adjustments made per above comments)
3200 for Houston

by Alger on Mar 19, 2013 11:38 am • linkreport

oboe - well thats mostly inside the beltway FFX and MoCo. Inside City of Alex, inside the beltway PG, and to some extent, ArlCo, already do their bit (if not as much as DC). This would make McLean pay, but leave Great Falls off the hook. Ditto for ChevyChase and Bethesda vs Potomac.

I've seen folks from McLean say how heroic they are for supporting poor folks in the rest of FFX county, as compared to having more local school districts.

by AWalkerInTheCity on Mar 19, 2013 11:39 am • linkreport

Amended, given the new area figures, we are Houston.

by Alger on Mar 19, 2013 11:40 am • linkreport

Amen to question about what if this were a state. Also to the word metonymy. I assume from context it means a word that makes people hate you or something like that. I never did AP English.

If it were a state, every exit off the beltway going into Greater DC would have a toll booth. Ka-ching!

by Ward 1 Guy on Mar 19, 2013 12:01 pm • linkreport

The area of DC, Arlington and Alexandria is 10x10miles=100 square miles, plus a bit of extra Alexandria....

by Jasper on Mar 19, 2013 12:05 pm • linkreport

If this were a state, it would still be the smallest (about 1/5 the size of Rhode Island) and it would be the 39th most populous (between WV and ID).

Metonymy (wow my browser thinks that is a typo) is substituting one concept for another when using a figure of speech. E.g. lots of people use Washington in writing or speech as a placeholder for "the US government" or "the US congress."

by MLD on Mar 19, 2013 12:09 pm • linkreport

Also, are we comparing to the City of LA, or LA county?

by Jasper on Mar 19, 2013 12:18 pm • linkreport

I'm sure that's LA city. The county would be much bigger and much more populous

by Alan B. on Mar 19, 2013 12:44 pm • linkreport

Better question: What if it was a state?
The other parts of Maryland and Virginia would be better-represented in their respective state governments? (Yuk, yuk, yuk.)

Also hopping onto the "metonymy" bandwagon. It's a great word - not my favorite in the English language (that would be a tossup between "quincunx" and "cephalophore"*), but close.

*Neither of these is transit-related. They're just really, really cool.

by Ser Amantio di Nicolao on Mar 19, 2013 12:49 pm • linkreport

Just to recap: 265ish square miles, minus approximately 17 square miles for water, leaving you with about 248 square miles of land area. 1,700,000/248 = 7056 persons per square mile... in 2010.

According to 2012 census estimates The District alone has added about 30,000 people since then, Arlington has added about 13,000, and Alexandria has added about 7,000. That's 50,000 in those three jurisdictions alone. That bumps the number up to about 1.8 million, not counting any growth in the other census tracts outside those jurisdictions.

1.8 million people/248 square miles is 7258 persons per square mile, minimum. In cities over 250,000 people, that would drop DC from 9th most densely populated to 12th, bumping us below Long Beach, Los Angeles, and Baltimore.

by Dave Murphy on Mar 19, 2013 1:23 pm • linkreport

given the numbers I crunched above, we would be slightly less than half the population of LA, and about 800 persons per square mile less dense.

by Dave Murphy on Mar 19, 2013 1:24 pm • linkreport

Dave Alpert: can you give a complete update of the data.

by SJE on Mar 19, 2013 1:56 pm • linkreport

Also: not only do we need to take out water, but all areas that are legally uninhabitable. DC has two very large parks in its boundaries: Rock Creek, and the Mall complex. The Federal buildings occupy a lot of space, and are not as readily comparable to other offices, as they are legally uninhabitable (except for 1600 Penn). By comparison, Sears Tower in Chicago has both offices and residents. The State government functions in Austin do not, IMO, take up anywhere near as much space as the giant monuments and offices in DC.

by SJE on Mar 19, 2013 2:00 pm • linkreport


There are parks in these other cities I would imagine as well.

by Kyle-W on Mar 19, 2013 2:37 pm • linkreport

Also: not only do we need to take out water, but all areas that are legally uninhabitable. DC has two very large parks in its boundaries: Rock Creek, and the Mall complex.

Other cities have uninhabitable areas as well -- Central Park, Pelham Bay Park (Bronx), Lincoln Park (Chicago), Grant Park (Chicago), Griffith Park (LA), Golden Gate Park (SF) etc.

by Scoot on Mar 19, 2013 2:49 pm • linkreport

SJE: I got some updated numbers on land and water area, and so I made a table that shows the stats to the best accuracy that I know of right now.

by David Alpert on Mar 19, 2013 2:50 pm • linkreport

while we're at it, can someone tell the guy who did the maps (which are good BTW) that the density at Seminary and I395 is Southern Towers? he seemed to want some info on that.

by AWalkerInTheCity on Mar 19, 2013 2:55 pm • linkreport

"Wouldn't that tiny point at the bottom near the Potomac River actually be outside the Beltway"

Yes it is, but it gets in on a peculiarity: the first marker stone is at the south end of it. Not including Jones Point would exclude a small fragment of the District of Columbia from being part of "Beltway DC."

by Another Nick on Mar 19, 2013 3:51 pm • linkreport

Of course other cities have uninhabitable land, too. But, they also have water area and we take those out for all cities. It would be interesting to remove park land along with water for all cities and recalculate. We take out water area because we can easily find the data. Is park land area data easily accessible?

Of course, there are small strips of water in different cities that do have population.

by jh on Mar 19, 2013 4:17 pm • linkreport

I recognize that other cities have park land and other legally uninhibatable areas. Lets take them out to be fair. So, NYC would take out Central Park, Battery Park, the UN, and some other area. My thesis is that the area inside the beltway has a lot more (proportionally) taken by government. The Mall and Federal complex, Pentagon, NIH. The embassies, too. Lets see the numbers.

by SJE on Mar 19, 2013 5:36 pm • linkreport

why does legally uninhabitable matter? Lots of cities have office buildings that are NOT multiuse, that serve the same funtions as the UN or the Pentagon. just because one is nonresidential by law, and the other is because thats the way things were built, does not change the actual density of the remaining residential/mixed use areas.

by AWalkerInTheCity on Mar 19, 2013 5:51 pm • linkreport

You could see how much sq. footage is subject to property taxes and divide by the number but you would have to do that for all cities to compare to DC otherwise it's meanigless

by Drumz on Mar 19, 2013 6:32 pm • linkreport

It can be instructive to look at the area inside the beltway as one entity, one "city."

To a large extent, many neighborhoods and communities within the Beltway are serviced via Metrorail. An individual who resides in, say, College Park, but works in Merrifield, is able to commute without a personal vehicle. Not surprisingly, the ability to commute via transit is mostly confined to areas ITB. The same cannot be said for many communities farther out. To be sure, there's MTA and VRE, and a few extended-line Metro stations, but generally it's much more challenging and time consuming to travel to and from the more distant areas without a car -- that is, if it's possible at all.

When the issue of affordable housing is explored, it often centers on the very inner areas of the region: Arlington, Alexandria, DC, Bethesda. These are, of course, the increasingly expensive areas to live in, due primarily to their growing attractiveness to young people and others who value urban living and its associated amenities -- transit, culture, and so forth. But when one looks at the ITB area as a one city, a more complete affordable housing picture emerges. It's a view more representative of a typical urbanized city in which there are neighborhoods and enclaves featuring affordable housing and others not so.

Looking at the inside the beltway cities, counties and communities as one provides a perspective more complete and comprehensive than otherwise. This more complete picture paints the inner DC region as that of a typical large global city, with all the accompanying plusses and minuses.

by Sage on Mar 19, 2013 6:39 pm • linkreport

Isn't population density figured by "land" area/population?

The District's land area comprises 61.4 sq. miles. With its official 601,723 population (2010 census), DC's population density is 9,800 per sq. mile. Using the 2012 population estimate of 632,323 produces a density of 10,298 sq. mile. These figures are substantially above the number shown in the table above.

by Sage on Mar 19, 2013 7:01 pm • linkreport

Sorry folks. My area error had to do with using the wrong projection. I fixed it. Now using Maryland state plane.

Population and land estimates from other cities are from Wikipedia.

by Michael Rodriguez on Mar 19, 2013 8:52 pm • linkreport

FYI: beware of the WGS Web Mercator (Auxiliary Sphere) projection in ArcGIS. For zoomed in at municipal level, it can create some funky stuff over a base layer. Best to use State Plane, as I did in my correction.

by Michael Rodriguez on Mar 19, 2013 10:21 pm • linkreport

AWITC: my point about "legally uninhabitable" is, in part, to distinguish between the choices that are available to a city versus those that are not. Chicago can choose whether to keep an area light industrial or make it mixed use. NYC already did that with the West side. DC does not have that choice in large part because the Feds occupy a large chunk of the real estate and decide what to do there.

We can also have fun with the numbers based on what choices are available. For example, no city is going to seriously change large chunks of land that are not available for other reasons. e.g. Airports. Large parks and monuments, a seaport. The San Andreas fault running along the peninsula near San Francisco.

yes, this makes it more difficult, but it also allows us to consider what land use policies are available.

by SJE on Mar 19, 2013 11:29 pm • linkreport

Perhaps the various concerns could be addressed by noting total jobs in the area in addition to population since some commuter areas have outsized employment compared to population.

I think the post has value as it stands though because DC is a bit of an anomaly in terms of political boundaries.

On the otherhand, I think the NY/NJ border has a related result if you look at actual population distribution in the area, Newark, Hudson County, and maybe (parts of) Bergen County might as well be another borough and one could reasonably argue are more closely integrated with Manhattan than Staten Island and parts of Queens.

by Alan B. on Mar 20, 2013 8:56 am • linkreport

Ward 1 Guy: Metonymy (pron.: /mɨˈtɒnɨmi/ mi-tonn-ə-mee)[1] is a figure of speech used in rhetoric in which a thing or concept is not called by its own name, but by the name of something intimately associated with that thing or concept. Metonyms can be either real or fictional concepts representing other concepts real or fictional, but they must serve as an effective and widely understood second name for what they represent.
For instance, "Hollywood" is used as a metonym (an instance of metonymy) for the US cinema industry, because of the fame and cultural identity of Hollywood, a district of the city of Los Angeles, California, as the historical center of film studios and film stars

by James on Mar 20, 2013 9:45 am • linkreport

i don't really think comparing inside-the-beltway dc (or dc proper for that matter) to los angeles or any other newer, western city is really that useful. older, eastern cities tend to have compact, simple geometries, whereas newer western cities have strange borders and enclaves and whatnot that end up both excluding some dense, urban areas close to the core and including more suburban areas far from the core. a better comparison than just the city of los angeles would be either superimposing the exact area of inside-the-beltway dc on the los angeles area, or delineating a portion of the LA area using some physical boundary, as the beltway was used for DC. here's a quick density map i threw together for the latter approach, wherein i used just the los angeles basin, using the surrounding mountains as the physical boundary. this excludes the san fernando valley, much of which is within the city limits of LA, but includes a lot of the southern and southeastern suburbs all the way down to irvine:

View Larger Map

for this region, the land area is 826 sq mi and the total population is 7,380,881. interestingly, after all that work it seems that the overall population density is relatively unchanged at 8,952 persons per sq mi. oh well. at least i had fun doing it.

by burgersub on Mar 20, 2013 11:05 am • linkreport

Miles Grant's comment is interesting, but the "state" he envisions should logically include not just "inside the Beltway," but the District, Montgomery and Prince Georges counties in Maryland, Arlington, Fairfax and Prince William counties, and Alexandria, Falls Church, and Fairfax cities in Virginnia. These jurisdictions arguably have much more in common with each other than they do with Annapolis or Richmond.

by Publius Washingtoniensis on Mar 20, 2013 11:10 am • linkreport

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