County Maps US

Macon County, Illinois

A county in Illinois, ranked 20 of 102 by population.

CountyFIPS 17115

Within Illinois
Macon County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Decatur, the county seat, located via the 2025 Census Gazetteer.

Download SVGFull Illinois map downloads

Population
99,300
-4,461 (-4.3%) since 2020
Land area
580.5
square miles. A further 0.9% of the total area is water
Population density
171
people per square mile, computed rather than published
County seat
Decatur
Seat of county government.
Established
1829
196 years ago
Largest city
Decatur city
Population 67,884.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Macon County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Macon County, Illinois from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 730 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Macon County ranks

Position among the 102 counties of Illinois, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IllinoisNationally
Population99,30020th of 102628th of 3,144
Land area580.5 sq mi38th of 1021,696th of 3,144
Population density171 per sq mi17th of 102626th of 3,144
Median household income$62,66670th of 1021,830th of 3,143

Full data for Macon County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population99,300Vintage 2025 Population Estimates
Population in 2020103,761Vintage 2025 Population Estimates
2020 estimates base?103,995Vintage 2025 Population Estimates
Land area580.5 sq mi2025 Gazetteer Files
Water area5.2 sq mi2025 Gazetteer Files
Total area585.8 sq mi2025 Gazetteer Files
Population density?171 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$62,666American Community Survey 2020-2024 5-Year Estimates
Median home value$127,300American Community Survey 2020-2024 5-Year Estimates
Median age40.6American Community Survey 2020-2024 5-Year Estimates
Households43,468American Community Survey 2020-2024 5-Year Estimates
Housing units49,630American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-334
1,025 births, 1,359 deaths
Net migration
-319
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 7 areas bordering Macon County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Christian CountyIllinois21 mi33,443
De Witt CountyIllinois21 mi15,118
Piatt CountyIllinois18 mi16,791
Moultrie CountyIllinois13 mi14,371
Logan CountyIllinois13 mi27,182
Shelby CountyIllinois11 mi20,576
Sangamon CountyIllinois7.1 mi194,170

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 102 counties of Illinois

Open the interactive Illinois county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.