• county
  • FIPS 17147
  • Largest town: Monticello

Piatt County, Illinois

Piatt County had 16,628 residents in the Census Vintage 2024 estimate, on 439.2 square miles of land. It ranks 62nd of 102 in Illinois by population and 64th by land area.

Population
16,628
#62 of 102 in Illinois · #1,997 in US
Area
439.2 sq mi
#64 of 102 in Illinois · #2,307 in US
Density
38 / sq mi
#63 of 102 in Illinois · #1,722 in US
Median household income
$81,611
#13 of 102 in Illinois · #418 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Piatt County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Piatt County

Piatt County population, land area and income

Piatt County had 16,628 residents in the Census Vintage 2024 estimate, on 439.2 square miles of land. It ranks 62nd of 102 in Illinois by population and 64th by land area. That works out to 37.9 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Illinois has 24,447 residents; Piatt County is somewhat smaller.

Its SAIPE 2023 median household income of $81,611 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

16,628

3144th1st

1997th of 3,144 (US)

Land area

439 sq mi

3144th1st

2307th of 3,144 (US)

Density

37.9 / sq mi

3144th1st

1722nd of 3,144 (US)

Median household income

$81,611

3143rd1st

418th of 3,143 (US)

Rank within Illinois (102)

Population

16,628

102nd1st

62nd of 102 (IL)

Land area

439 sq mi

102nd1st

64th of 102 (IL)

Density

37.9 / sq mi

102nd1st

63rd of 102 (IL)

Median household income

$81,611

102nd1st

13th of 102 (IL)

How Piatt County's population changed since 2020

Piatt County lost 55 residents between the July 2020 and July 2024 estimates, a drop of 0.3%. That ranks 22nd of 102 in Illinois for growth. The median Illinois county changed by -1.7%, and the state as a whole by -0.7%.

Since the April 2020 estimates base, Piatt County recorded 666 births and 809 deaths, a natural change of -143. Net international migration added +3 and net domestic migration, people moving to or from other US counties, came to +89. The largest single component was natural change, which removed 143 people.

16.7k202016.8k202116.7k202216.7k202316.6k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
666
Deaths
809
Net international migration
+3
Net domestic migration
+89
Change, July 2023 to July 2024
-92

Where Piatt County is

The Census internal point of Piatt County is at 40.009000, -88.592400. It sits in UTM zone 16N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Piatt County outlined. Dots are towns of 1,000+ people with residents in it.

Piatt County: -0.3%Hamilton County: -2.2%Williamson County: -0.1%Edgar County: -2.4%Macoupin County: -2.3%Marshall County: -1.3%Putnam County: +0.0%Richland County: -2.8%Washington County: -1.4%Lee County: -1.5%Douglas County: +0.2%Cook County: -1.6%Effingham County: -0.3%Edwards County: -3.6%Cass County: -2.0%Clay County: -3.4%Knox County: -2.2%LaSalle County: -0.9%Cumberland County: -1.3%Warren County: -3.7%Moultrie County: -0.9%Menard County: -2.5%Fayette County: -1.5%Boone County: -0.0%Lawrence County: -3.2%Marion County: -3.2%Champaign County: +3.0%Clark County: -2.4%Ford County: -0.4%Wayne County: -1.4%Logan County: -1.4%Grundy County: +2.5%Jasper County: -1.8%Crawford County: -1.3%McDonough County: -1.7%Clinton County: +0.5%Perry County: -3.0%Montgomery County: -2.2%Henry County: -2.0%Livingston County: -1.2%Scott County: -3.8%Alexander County: -11.2%Bureau County: -2.2%Brown County: +1.1%Mason County: -3.9%Calhoun County: -4.1%Greene County: -4.3%Coles County: -1.4%Kendall County: +8.2%Lake County: +0.7%Mercer County: -2.2%St. Clair County: -2.3%Wabash County: -3.0%Bond County: -1.7%DuPage County: +0.6%Gallatin County: -5.2%Stephenson County: -3.3%McHenry County: +1.9%White County: -3.0%Saline County: -3.9%Christian County: -2.2%Sangamon County: -1.0%Massac County: -3.6%Macon County: -2.9%Johnson County: -0.0%Jo Daviess County: -2.6%Peoria County: -1.0%DeKalb County: +1.0%Pope County: -1.5%De Witt County: -0.9%Schuyler County: -1.7%Fulton County: -3.1%Ogle County: -0.8%Jersey County: -1.6%Iroquois County: -3.3%Kankakee County: -0.9%Rock Island County: -1.1%Pulaski County: -5.8%Kane County: +0.9%Union County: -2.4%Whiteside County: -1.7%Woodford County: -0.3%Carroll County: -1.5%Adams County: -2.3%Hardin County: -2.6%Madison County: -1.0%Hancock County: -3.1%Monroe County: +0.0%Tazewell County: -1.1%Jackson County: -0.1%Vermilion County: -3.9%Randolph County: -0.6%McLean County: +0.5%Morgan County: -2.6%Shelby County: -1.7%Will County: +1.7%Winnebago County: -0.4%Jefferson County: -2.4%Stark County: -2.2%Henderson County: -4.5%Pike County: -2.6%Franklin County: -1.8%
Change 2020 to 2024
  1. < -3.0%
  2. < -2.2%
  3. < -1.4%
  4. < -0.3%
  5. ≥ -0.3%
no data

Orange pin: Piatt County internal point. Dark pin: Springfield.

Internal point

Decimal
40.009000, -88.592400
DMS
40°00'32.40"N 88°35'32.64"W
UTM
16N 364088.0E 4429970.5N
Geohash
dp15852vr
Plus code
86GH2C55+J2

Towns in Piatt County

4 incorporated places of 1,000+ people have residents in Piatt County, 9,338 people together, or 56% of the county. Each figure counts only the part of the town inside Piatt County; towns marked "part" extend into another county. The largest is Monticello with 6,010.

  1. 01Monticello6,010
  2. 02Bement1,452
  3. 03Cerro Gordo1,295
  4. 04Atwood (part)581
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Piatt County

The Census 2024 county adjacency file lists 6 neighbors for Piatt County. The most populous is Champaign County, IL, with 212,374 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 58.2 miles WSW of Piatt County's internal point in a straight line. The nearest place of 100,000 or more is Springfield, IL (population 112,949), 57.8 miles away. The nearest place of 10,000 or more is Mahomet, IL (population 10,619), 16.5 miles away.

Piatt County FIPS code

The FIPS code of Piatt County is 17147: state code 17 for Illinois plus county code 147. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $81,611.

Questions people ask

What is the population of Piatt County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 16,628. That is down 55 people (0.3%) from the July 2020 estimate of 16,683.

What is the FIPS code of Piatt County?

17147. The first two digits (17) are Illinois; the last three (147) identify the county.

What is the largest town in Piatt County?

Monticello, with 6,010 residents inside Piatt County in 2024.

Which counties border Piatt County?

6 county-equivalents border it in the Census 2024 adjacency file: Champaign County, IL; McLean County, IL; Macon County, IL; Douglas County, IL; De Witt County, IL; Moultrie County, IL.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.