• county
  • FIPS 26147
  • Largest town: Port Huron

St. Clair County, Michigan

St. Clair County had 160,308 residents in the Census Vintage 2024 estimate, on 721.5 square miles of land. It ranks 13th of 83 in Michigan by population and 24th by land area.

Population
160,308
#13 of 83 in Michigan · #436 in US
Area
721.5 sq mi
#24 of 83 in Michigan · #1,239 in US
Density
222 / sq mi
#17 of 83 in Michigan · #533 in US
Median household income
$68,831
#21 of 83 in Michigan · #1,077 in US

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

St. Clair County within Michigan. Pin: Lansing.

Measure from here

Tools and pages that start from St. Clair County

St. Clair County population, land area and income

St. Clair County had 160,308 residents in the Census Vintage 2024 estimate, on 721.5 square miles of land. It ranks 13th of 83 in Michigan by population and 24th by land area. That works out to 222.2 people per square mile, 2.3 times the US average of 96.3, and in the top quarter nationally.

The median county-equivalent in Michigan has 38,041 residents, so St. Clair County is 4.2 times that size.

Its SAIPE 2023 median household income of $68,831 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

160,308

3144th1st

436th of 3,144 (US)

Land area

722 sq mi

3144th1st

1239th of 3,144 (US)

Density

222.2 / sq mi

3144th1st

533rd of 3,144 (US)

Median household income

$68,831

3143rd1st

1077th of 3,143 (US)

Rank within Michigan (83)

Population

160,308

83rd1st

13th of 83 (MI)

Land area

722 sq mi

83rd1st

24th of 83 (MI)

Density

222.2 / sq mi

83rd1st

17th of 83 (MI)

Median household income

$68,831

83rd1st

21st of 83 (MI)

How St. Clair County's population changed since 2020

St. Clair County lost 86 residents between the July 2020 and July 2024 estimates, a drop of 0.1%. That ranks 63rd of 83 in Michigan for growth. The median Michigan county changed by +0.9%, and the state as a whole by +0.7%.

Since the April 2020 estimates base, St. Clair County recorded 6,186 births and 8,785 deaths, a natural change of -2,599. Net international migration added +353 and net domestic migration, people moving to or from other US counties, came to +2,134. The largest single component was natural change, which removed 2,599 people.

160.4k2020160.2k2021159.9k2022160.3k2023160.3k2024
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
6,186
Deaths
8,785
Net international migration
+353
Net domestic migration
+2,134
Change, July 2023 to July 2024
+28

Where St. Clair County is

The Census internal point of St. Clair County is at 42.928800, -82.668900. It sits in UTM zone 17N. The map shades Michigan's 83 county-equivalents by population change from 2020 to 2024, darker for faster growth, with St. Clair County outlined. Dots are towns of 1,000+ people with residents in it.

Calhoun County: -0.3%Benzie County: +2.9%Newaygo County: +2.8%Antrim County: +4.6%Montcalm County: +4.0%Kalamazoo County: +1.1%Isabella County: +0.9%Ingham County: +1.9%Jackson County: +0.0%Kent County: +2.2%Oceana County: +1.1%Roscommon County: +2.0%Clare County: +1.8%Gladwin County: +2.5%Branch County: +2.9%Iosco County: +0.7%Bay County: -1.1%Shiawassee County: -0.0%Ionia County: -1.0%Otsego County: +3.8%Alcona County: +4.3%Missaukee County: +1.1%Crawford County: +4.7%Lapeer County: +0.7%Arenac County: +0.5%Gogebic County: -0.9%Marquette County: +2.2%Alpena County: +0.1%Lenawee County: -1.6%Berrien County: -1.1%Leelanau County: +2.5%Clinton County: +1.1%Alger County: -1.6%Gratiot County: -0.8%St. Joseph County: +0.4%Van Buren County: +0.7%Dickinson County: +0.3%Charlevoix County: +0.3%Sanilac County: -0.5%Wexford County: +2.3%Houghton County: +2.1%Saginaw County: -1.1%Kalkaska County: +3.8%Ottawa County: +3.1%Presque Isle County: +1.8%Eaton County: +0.3%Barry County: +2.3%Lake County: +7.5%Cheboygan County: +1.5%Wayne County: -1.0%Macomb County: +0.7%Oscoda County: +4.4%Emmet County: -0.5%Ontonagon County: +0.4%Schoolcraft County: +1.5%Monroe County: +0.7%Tuscola County: -1.0%Luce County: -1.3%Menominee County: -1.7%Mason County: +0.2%Muskegon County: +1.5%Baraga County: +0.3%Genesee County: -0.9%Grand Traverse County: +1.3%Washtenaw County: +0.5%Huron County: -1.9%Cass County: -0.0%Delta County: -0.5%Montmorency County: +7.2%Oakland County: +1.9%Chippewa County: -1.5%Keweenaw County: +5.0%Hillsdale County: -0.3%Manistee County: +1.8%Allegan County: +1.5%Mecosta County: +3.8%Iron County: +0.8%Osceola County: +2.5%St. Clair County: -0.1%Livingston County: +1.5%Ogemaw County: +1.0%Midland County: +0.6%Mackinac County: +3.1%
Change 2020 to 2024
  1. < -0.5%
  2. < +0.5%
  3. < +1.5%
  4. < +2.5%
  5. ≥ +2.5%
no data

Orange pin: St. Clair County internal point. Dark pin: Lansing.

Internal point

Decimal
42.928800, -82.668900
DMS
42°55'43.68"N 82°40'8.04"W
UTM
17N 363812.3E 4754259.3N
Geohash
dpthnyfq7
Plus code
86JVW8HJ+GC

Towns in St. Clair County

9 incorporated places of 1,000+ people have residents in St. Clair County, 56,288 people together, or 35% of the county. Each figure counts only the part of the town inside St. Clair County; towns marked "part" extend into another county. The largest is Port Huron with 28,342.

  1. 01Port Huron28,342
  2. 02Marysville9,868
  3. 03St. Clair5,824
  4. 04Algonac4,111
  5. 05Marine City4,006
  6. 06Capac1,946
  7. 07Yale1,878
  8. 08Memphis (part)312
  9. 09Richmond (part)1
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering St. Clair County

The Census 2024 county adjacency file lists 3 neighbors for St. Clair County. The most populous is Macomb County, MI, with 886,175 residents. Distances run between Census internal points in a straight line.

Distance to Lansing and the nearest big city

Lansing is 96.5 miles W of St. Clair County's internal point in a straight line. The nearest place of 100,000 or more is Sterling Heights, MI (population 134,342), 30.2 miles away. The nearest place of 10,000 or more is Port Huron, MI (population 28,342), 12.7 miles away.

St. Clair County FIPS code

The FIPS code of St. Clair County is 26147: state code 26 for Michigan 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 $68,831.

Questions people ask

What is the population of St. Clair County, Michigan?

The Census Vintage 2024 estimate for July 1, 2024 is 160,308. That is down 86 people (0.1%) from the July 2020 estimate of 160,394.

What is the FIPS code of St. Clair County?

26147. The first two digits (26) are Michigan; the last three (147) identify the county.

What is the largest town in St. Clair County?

Port Huron, with 28,342 residents inside St. Clair County in 2024.

Which counties border St. Clair County?

3 county-equivalents border it in the Census 2024 adjacency file: Macomb County, MI; Lapeer County, MI; Sanilac County, MI.

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.