Imperial County area

Population and density of Imperial County

The Census Bureau estimates that 181,411 people lived in Imperial County on July 1, 2025. That ranks #389 of 3,222 county equivalents nationally and #31 of 58 in California. Since the April 1, 2020 estimates base of 179,705, the population has grown by 1,706 (+0.9%), compared with −0.5% for California as a whole.

With 4,175.5 square miles of land, that is 43 people per square mile (17 per km²), placing Imperial County #1,677 nationally for density and #41 in California. The median county equivalent has 47 people per square mile; the California median is 112. Put another way, there are about 15 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 Imperial County

7 incorporated places lie at least partly in Imperial County. Together they are home to 146,961 people (81%); the other 34,450 (19%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is El Centro city, with 44,382 residents in the county. Among places with at least 1,000 residents in 2020, Imperial city grew fastest since then (+9.7%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Imperial County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Imperial County is a central county of the El Centro, CA Metropolitan Statistical Area. Imperial County is the area’s only county equivalent, so the metro area has the same 4,175.5 square miles of land. By combined land it ranks #69 of 393 metropolitan areas, and #255 by population.

ZIP codes

18 ZIP Code Tabulation Areas have land in Imperial County; 15 of them have most of their land inside the county, and the others mainly cover neighboring areas.

920049222292225922279223192233922439224992250922519225792259922669227392274922759228192283

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Imperial County

Imperial County shares a land border with 4 county equivalents, including 2 in Arizona. Each of them has more land than Imperial County. The largest neighbor is Riverside County (7,209 mi²) and the smallest is San Diego County (4,210.9 mi²). Together with its neighbors, Imperial County forms a block of 25,605.7 mi² of land, of which it holds 16.3%.

How big is Imperial County compared with U.S. states?

Imperial County has more land than 2 of the 50 states. It is about 2.1 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.2 times as much land (4,842.5 mi²). California’s county land could hold about 37 areas the size of Imperial County.

Another way to picture it: the same land area would fill a square about 64.6 miles (104 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 Imperial County?

Imperial County has more land than 3,107 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 Imperial County at #111 nationally by total area, 4 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 6.8%, compared with a national county-equivalent median of 1.2% — 5.6 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 Imperial County 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.