Audrain County area

Population and density of Audrain County

The Census Bureau estimates that 24,528 people lived in Audrain County on July 1, 2025. That ranks #1,682 of 3,222 county equivalents nationally and #44 of 115 in Missouri. Since the April 1, 2020 estimates base of 24,963, the population has declined by 435 (−1.7%), compared with +1.9% for Missouri as a whole.

With 692.3 square miles of land, that is 35 people per square mile (14 per km²), placing Audrain County #1,864 nationally for density and #51 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 18 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 Audrain County

9 incorporated places lie at least partly in Audrain County. Together they are home to 15,880 people (64.7%); the other 8,648 (35.3%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Mexico city, with 11,558 residents in the county. Among places with at least 1,000 residents in 2020, Mexico city grew fastest since then (+0.8%).

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

Metropolitan area

Audrain County is a central county of the Mexico, MO Micropolitan Statistical Area. Audrain County is the area’s only county equivalent, so the micro area has the same 692.3 square miles of land. By combined land it ranks #309 of 542 micropolitan areas, and #484 by population. It belongs to the Columbia-Jefferson City-Moberly, MO Combined Statistical Area.

ZIP codes

14 ZIP Code Tabulation Areas have land in Audrain County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

6334563352633596338263384652316523265240652436526465265652806528465285

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 Audrain County

Audrain County shares a land border with 7 county equivalents. It has more land than 6 of them. The largest neighbor is Callaway County (834.6 mi²) and the smallest is Ralls County (469.8 mi²). Together with its neighbors, Audrain County forms a block of 5,018 mi² of land, of which it holds 13.8%.

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

Audrain County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.5 times as much. Missouri’s county land could hold about 99 areas the size of Audrain County.

Another way to picture it: the same land area would fill a square about 26.3 miles (42.3 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 Audrain County?

Audrain County has more land than 1,870 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 Audrain County at #1,447 nationally by total area, 95 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 0.7%, compared with a national county-equivalent median of 1.2% — 0.5 percentage points lower. 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 Audrain 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.