Logan County area

Population and density of Logan County

The Census Bureau estimates that 27,182 people lived in Logan County on July 1, 2025. That ranks #1,583 of 3,222 county equivalents nationally and #49 of 102 in Illinois. Since the April 1, 2020 estimates base of 27,988, the population has declined by 806 (−2.9%), compared with −0.8% for Illinois as a whole.

With 618.1 square miles of land, that is 44 people per square mile (17 per km²), placing Logan County #1,666 nationally for density and #52 in Illinois. The median county equivalent has 47 people per square mile; the Illinois median is 44. 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 Logan County

11 incorporated places lie at least partly in Logan County. Together they are home to 18,471 people (68%); the other 8,711 (32%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Lincoln city, with 12,981 residents in the county.

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

Metropolitan area

Logan County is a central county of the Lincoln, IL Micropolitan Statistical Area. Logan County is the area’s only county equivalent, so the micro area has the same 618.1 square miles of land. By combined land it ranks #345 of 542 micropolitan areas, and #460 by population. It belongs to the Springfield-Jacksonville-Lincoln, IL Combined Statistical Area.

ZIP codes

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

6172161723617496175161754625126251862519625416254362548626136263462635626436265662666626716268262693

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 Logan County

Logan County shares a land border with 7 county equivalents. It has more land than 4 of them. The largest neighbor is McLean County (1,183.2 mi²) and the smallest is Menard County (314.4 mi²). Together with its neighbors, Logan County forms a block of 5,147.9 mi² of land, of which it holds 12%.

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

Logan County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.7 times as much. Illinois’s county land could hold about 90 areas the size of Logan County.

Another way to picture it: the same land area would fill a square about 24.9 miles (40 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 Logan County?

Logan County has more land than 1,662 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 Logan County at #1,681 nationally by total area, 121 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 0.1%, compared with a national county-equivalent median of 1.2% — 1 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 Logan 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.