Macon County area

Population and density of Macon County

The Census Bureau estimates that 99,300 people lived in Macon County on July 1, 2025. That ranks #633 of 3,222 county equivalents nationally and #20 of 102 in Illinois. Since the April 1, 2020 estimates base of 103,995, the population has declined by 4,695 (−4.5%), compared with −0.8% for Illinois as a whole.

With 580.5 square miles of land, that is 171 people per square mile (66 per km²), placing Macon County #701 nationally for density and #17 in Illinois. The median county equivalent has 47 people per square mile; the Illinois median is 44. Put another way, there are about 3.7 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 Macon County

12 incorporated places lie at least partly in Macon County. Together they are home to 86,914 people (87.5%); the other 12,386 (12.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Decatur city, with 67,884 residents in the county.

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

Metropolitan area

Macon County is a central county of the Decatur, IL Metropolitan Statistical Area. Macon County is the area’s only county equivalent, so the metro area has the same 580.5 square miles of land. By combined land it ranks #343 of 393 metropolitan areas, and #371 by population.

ZIP codes

27 ZIP Code Tabulation Areas have land in Macon County; 16 of them have most of their land inside the county, and the others mainly cover neighboring areas.

617496175661818618306188261914619256193762501625136251462521625226252362526625326253562537625396254362544625476254962550625516255462573

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 Macon County

Macon County shares a land border with 7 county equivalents. It has more land than 3 of them. The largest neighbor is Sangamon County (868.2 mi²) and the smallest is Moultrie County (336 mi²). Together with its neighbors, Macon County forms a block of 4,707.5 mi² of land, of which it holds 12.3%.

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

Macon County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Illinois’s county land could hold about 96 areas the size of Macon County.

Another way to picture it: the same land area would fill a square about 24.1 miles (38.8 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 Macon County?

Macon County has more land than 1,526 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 Macon County at #1,799 nationally by total area, 103 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 0.9%, compared with a national county-equivalent median of 1.2% — 0.3 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 Macon 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.