Sumner County area

Population and density of Sumner County

The Census Bureau estimates that 22,312 people lived in Sumner County on July 1, 2025. That ranks #1,765 of 3,222 county equivalents nationally and #25 of 105 in Kansas. Since the April 1, 2020 estimates base of 22,388, the population has declined by 76 (−0.3%), compared with +1.3% for Kansas as a whole.

With 1,181.7 square miles of land, that is 19 people per square mile (7.3 per km²), placing Sumner County #2,361 nationally for density and #37 in Kansas. The median county equivalent has 47 people per square mile; the Kansas median is 8.1. Put another way, there are about 34 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 Sumner County

12 incorporated places lie at least partly in Sumner County. Together they are home to 14,285 people (64%); the other 8,027 (36%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Wellington city, with 7,541 residents in the county. Among places with at least 1,000 residents in 2020, Conway Springs city grew fastest since then (+4.3%).

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

Metropolitan area

Sumner County is an outlying county of the Wichita, KS Metropolitan Statistical Area. Its 4 county equivalents have 663,809 residents on 4,148.1 square miles of land; Sumner County accounts for 28.5% of the land and 3.4% of the residents. By combined land it ranks #70 of 393 metropolitan areas, and #91 by population. It belongs to the Wichita-Arkansas City-Winfield, KS Combined Statistical Area.

ZIP codes

18 ZIP Code Tabulation Areas have land in Sumner County; 13 of them have most of their land inside the county, and the others mainly cover neighboring areas.

670046701367018670226702667031670496705167103671056710667110671186711967120671406714667152

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 Sumner County

Sumner County shares a land border with 6 county equivalents, including 2 in Oklahoma. It has more land than every one of them. The largest neighbor is Cowley County (1,125.7 mi²) and the smallest is Harper County (801.3 mi²). Together with its neighbors, Sumner County forms a block of 6,889.5 mi² of land, of which it holds 17.2%.

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

Sumner County has more land than 1 of the 50 states. It is about 1.1 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.6 times as much land (1,948.6 mi²). Kansas’s county land could hold about 69 areas the size of Sumner County.

Another way to picture it: the same land area would fill a square about 34.4 miles (55.3 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 Sumner County?

Sumner County has more land than 2,704 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 Sumner County at #599 nationally by total area, 81 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 0.3%, compared with a national county-equivalent median of 1.2% — 0.9 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 Sumner 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.