Demographics of St. Clair County, Michigan

St. Clair County, Michigan had 160,486 people on July 1, 2025, by the Census Bureau’s estimate: +100 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

St. Clair County, in four figures

160,486
Population: July 1, 2025, Vintage 2025 estimate.; +0.1%
Change since July 2020: +100 people.; 44.5 ±0.2
Median age: ACS 2020–⁠2024.; $71,270 ±$1,351
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

St. Clair County, Michigan's population grew 0.1% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of St. Clair County, Michigan's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

St. Clair County, Michigan's population grew 0.1% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of St. Clair County, Michigan's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	160,386	100.0	100.0
2021	160,268	99.9	100.2
2022	159,886	99.7	100.7
2023	160,279	99.9	101.6
2024	160,304	99.9	102.5
2025	160,486	100.1	103.1

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Population of St. Clair County, Michigan on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	160,386	+1	−122	0	+73
2021	160,268	−118	−792	+28	+491
2022	159,886	−382	−738	+80	+395
2023	160,279	+393	−489	+132	+784
2024	160,304	+25	−450	+139	+360
2025	160,486	+182	−461	+54	+584

Age, 2020–2024

The median age is 44.5 ±0.2: for men 43.4 ±0.4 and for women 45.5 ±0.2. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in St. Clair County by age, ACS 2020–2024
Age	People	Share	Michigan	United States
Under 5	7,752 ±44	4.8% ±<0.1	5.4% ±<0.1	5.6% ±<0.1
5 to 17	24,726 ±731	15.4% ±0.5	15.9% ±0.1	16.3% ±<0.1
18 to 24	12,103 ±560	7.6% ±0.3	9.2% ±0.1	9.1% ±<0.1
25 to 44	36,541 ±821	22.8% ±0.5	25.3% ±0.1	26.9% ±<0.1
45 to 64	46,450 ±848	29.0% ±0.5	25.6% ±0.1	24.8% ±<0.1
65 and over	32,649 ±973	20.4% ±0.6	18.6% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $71,270 ±$1,351, and income per person $38,214 ±$1,024, in 2024 dollars. The median is $72,875 ±$293 in Michigan and $80,734 ±$166 in the United States.

Households by income

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Households in St. Clair County by income, ACS 2020–2024
Household income	Households	Share	Michigan	United States
Under $25,000	9,889 ±689	14.6% ±1.0	15.8% ±0.1	14.6% ±<0.1
$25,000 to $49,999	13,249 ±755	19.5% ±1.1	18.7% ±0.2	16.7% ±<0.1
$50,000 to $74,999	12,623 ±738	18.6% ±1.1	16.8% ±0.1	15.5% ±<0.1
$75,000 to $99,999	9,380 ±601	13.8% ±0.9	13.2% ±0.1	12.6% ±<0.1
$100,000 to $149,999	12,606 ±758	18.6% ±1.1	17.3% ±0.2	17.5% ±<0.1
$150,000 to $199,999	5,223 ±485	7.7% ±0.7	8.6% ±0.1	9.6% ±<0.1
$200,000 or more	4,846 ±536	7.1% ±0.8	9.5% ±0.1	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in St. Clair County by age, ACS 2020–2024
Age	Below poverty	Rate	Michigan	United States
All ages	17,872 ±1,412	11.3% ±0.9	13.2% ±0.2	12.5% ±0.1
Under 18	4,986 ±561	15.7% ±1.7	17.6% ±0.3	16.1% ±0.1
18 to 59	8,909 ±758	10.9% ±0.9	12.7% ±0.2	11.6% ±0.1
60 and over	3,977 ±408	8.9% ±0.9	10.5% ±0.1	11.0% ±<0.1

Housing, 2020–2024

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Housing in St. Clair County, ACS 2020–2024
Measure	St. Clair County	Michigan	United States
Housing units	72,799 ±121	4,622,236 ±795	143,775,355 ±10,234
Occupied	93.2% ±0.8	88.2% ±0.2	89.9% ±0.1
Vacant	6.8% ±0.8	11.8% ±0.2	10.1% ±0.1
Owner occupied	80.8% ±1.2	73.2% ±0.3	65.2% ±0.3
Renter occupied	19.2% ±1.2	26.8% ±0.2	34.8% ±0.1
Median home value	$224,600 ±$3,575	$231,600 ±$642	$332,700 ±$236
Median gross rent	$1,029 ±$25	$1,129 ±$4	$1,413 ±$2
Median year built	1975 ±1	1972 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in St. Clair County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Michigan	United States
Hispanic or Latino	5,905 ±0	3.7% ±<0.1	5.9% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	143,658 ±399	89.7% ±0.2	72.4% ±<0.1	57.4% ±<0.1
Black alone, not Hispanic	3,395 ±369	2.1% ±0.2	13.1% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	785 ±167	0.5% ±0.1	3.4% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	178 ±56	0.1% ±<0.1	0.3% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 38	0% to < 0.1%	< 0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	521 ±240	0.3% ±0.1	0.5% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	5,764 ±508	3.6% ±0.3	4.5% ±0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in St. Clair County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Michigan	United States
Born in the state	140,218 ±1,009	87.5% ±0.6	76.0% ±0.1	57.3% ±<0.1
Born in another state	15,518 ±902	9.7% ±0.6	16.0% ±0.1	26.9% ±<0.1
Born a citizen outside the states	1,245 ±244	0.8% ±0.2	0.9% ±<0.1	1.7% ±<0.1
Born abroad	3,240 ±384	2.0% ±0.2	7.2% ±0.1	14.1% ±<0.1
Naturalized citizens	1,937 ±283	1.2% ±0.2	4.1% ±0.1	7.4% ±<0.1
Not citizens	1,303 ±224	0.8% ±0.1	3.1% ±0.1	6.8% ±<0.1

St. Clair County among the counties of Michigan

13th of 83 by population, July 2025. Every one is listed on the Michigan page.

Counties of Michigan near St. Clair County in population, July 2025
County	July 2025	Change since 2020
Ingham County	289,709	+1.7%
Kalamazoo County	263,795	+0.8%
Livingston County	197,315	+1.7%
Saginaw County	187,688	−1.1%
Muskegon County	177,901	+1.8%
St. Clair County	160,486	+0.1%
Jackson County	159,552	−0.4%
Monroe County	156,004	+0.7%
Berrien County	152,444	−1.3%
Calhoun County	133,408	−0.6%
Allegan County	123,188	+2.1%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026