District of Columbia area

Population and density of District of Columbia

The Census Bureau estimates that 693,645 people lived in District of Columbia on July 1, 2025. That ranks #101 of 3,222 county equivalents nationally. Since the April 1, 2020 estimates base of 689,544, the population has grown by 4,101 (+0.6%).

With 61.1 square miles of land, that is 11,348 people per square mile (4,381 per km²), placing District of Columbia #9 nationally for density. The median county equivalent has 47 people per square mile. Put another way, there are about 0.056 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in District of Columbia

Every resident of District of Columbia lives within Washington city. The city and the county equivalent cover the same territory, 61.1 square miles of land in the 2026 place Gazetteer, so there are no separate towns or unincorporated areas to list.

Metropolitan area

District of Columbia is a central county of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, in the Washington, DC-MD metropolitan division. Its 23 county equivalents have 6,465,724 residents on 6,033.7 square miles of land; District of Columbia accounts for 1% of the land and 10.7% of the residents. By combined land it ranks #35 of 393 metropolitan areas, and #7 by population. It belongs to the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area.

ZIP codes

57 ZIP Code Tabulation Areas have land in District of Columbia, and each lies mostly inside the county.

200012000220003200042000520006200072000820009200102001120012200152001620017200182001920020200242003220036200372004520052200572005920064202042022020230202402024520250202602031720319203732038820390204082041520418204222042720431205102051520520205302053520540205422055120560205652056620591

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering District of Columbia

District of Columbia shares a land border with 4 county equivalents, including 4 in Maryland and Virginia. It has more land than 2 of them. The largest neighbor is Montgomery County (493.1 mi²) and the smallest is Alexandria city (14.9 mi²). Together with its neighbors, District of Columbia forms a block of 1,077.8 mi² of land, of which it holds 5.7%.

How big is District of Columbia compared with U.S. states?

District of Columbia has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 17 times as much.

Another way to picture it: the same land area would fill a square about 7.82 miles (12.6 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about District of Columbia?

District of Columbia has more land than 109 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places District of Columbia at #3,132 nationally by total area, 19 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 10.6%, compared with a national county-equivalent median of 1.2% — 9.4 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside District of Columbia in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.