Clark County vs Mercer County

A side-by-side comparison of Clark County and Mercer County: population, income, housing, and more.

Clark County and Mercer County are counties in Illinois. This page compares them across population, income, housing, education, commuting, and how each has changed since 2019.

Mercer County has the higher population (15,619 vs 15,328 in Clark County). Mercer County has the higher median household income ($71,710 vs $70,625 in Clark County). Mercer County has the higher median home value ($139,300 vs $123,100 in Clark County).

Population, income & housing

	Clark County	Mercer County
Population	15,328	15,619
Median age	42.0 yrs	44.5 yrs
Median household income	$70,625	$71,710
Median home value	$123,100	$139,300
Median gross rent	$828	$757
Housing units	7,333	7,279
Homeownership rate	81.7%	82.7%
Bachelor's degree or higher	24.3%	18.9%
Unemployment rate	4.0%	3.1%

Trends (ACS 5-year, 2019–2023)

	Clark County	Mercer County
Population	15,716 → 15,328 (-2.5%)	15,589 → 15,619 (+0.2%)
Median household income	$56,531 → $70,625 (+24.9%)	$59,787 → $71,710 (+19.9%)
Median home value	$92,500 → $123,100 (+33.1%)	$107,600 → $139,300 (+29.5%)
Median gross rent	$687 → $828 (+20.5%)	$655 → $757 (+15.6%)

Clark County

Population

15,71615,328

Median household income

$56,531$70,625

Median home value

$92,500$123,100

Median gross rent

$687$828

Mercer County

Population

15,58915,619

Median household income

$59,787$71,710

Median home value

$107,600$139,300

Median gross rent

$655$757

Age & race/ethnicity

Age distribution (share)

	Clark County	Mercer County
Under 5	5.5%	4.8%
5 to 17	16.8%	16.2%
18 to 24	7.3%	7.5%
25 to 34	11.3%	10.3%
35 to 44	11.9%	12.0%
45 to 54	12.8%	12.6%
55 to 64	14.7%	15.0%
65 to 74	11.4%	12.3%
75 and over	8.2%	9.1%

Race & ethnicity (share)

	Clark County	Mercer County
White (non-Hispanic)	95.6%	93.5%
Black or African American	0.7%	0.6%
American Indian & Alaska Native	0.0%	0.1%
Asian	0.2%	0.3%
Native Hawaiian & Pacific Islander	0.0%	0.0%
Some other race	0.0%	0.0%
Two or more races	1.8%	2.2%
Hispanic or Latino	1.8%	3.3%

Educational attainment (age 25+)

Share of adults 25+

	Clark County	Mercer County
No high school diploma	8.0%	6.7%
High school graduate	35.3%	40.2%
Some college or associate's	32.5%	34.2%
Bachelor's degree	14.3%	12.6%
Graduate or professional degree	9.9%	6.3%

Commute to work

How workers get to work (share)

	Clark County	Mercer County
Drove alone	82.1%	81.4%
Carpooled	10.1%	8.0%
Public transit	0.3%	0.1%
Walked	1.2%	2.2%
Bicycle	0.0%	0.0%
Worked from home	5.4%	7.8%
Other means	0.8%	0.5%

Housing

Units in structure (share)

	Clark County	Mercer County
1-unit, detached	81.1%	87.6%
1-unit, attached	0.8%	0.9%
2 to 4 units	4.8%	4.2%
5 to 19 units	4.7%	2.4%
20 or more units	1.4%	1.5%
Mobile home & other	7.3%	3.3%

Poverty & households

	Clark County	Mercer County
Poverty rate	9.5%	7.9%
Average household size	2.28	2.41
Mean commute (minutes)	26	28
Median year structure built	1969	1960