Duncan township

County:: Mercer County
County Seat:: No
Area (mi²):: 36.636
State:: Illinois

Duncan township is located in Mercer County, Illinois. Duncan township has a 2025 population of 256. Duncan township is currently declining at a rate of 0% annually and its population has decreased by -0.78% since the most recent census, which recorded a population of 258 in 2020.

The average household income in Duncan township is $82,538 with a poverty rate of 7.84%. The median age in Duncan township is 48.8 years: 35.6 years for males, and 62.6 years for females.

Demographics

The racial composition of Duncan township includes 100% White, and smaller percentages for Black or African American, Native American, Asian, Native Hawaiian or Pacific Islander, other race, Two or more races and multiracial populations.

Population by Race

White

Black or African American

Native American

Asian

Native Hawaiian or Pacific Islander

Other race

Two or more races

Race	Population	Percentage (of total)
White	255	100%
Black or African American	0	0%
Native American	0	0%
Asian	0	0%
Native Hawaiian or Pacific Islander	0	0%
Other race	0	0%
Two or more races	0	0%

Duncan township Marital Status

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Duncan township's average per capita income is $40,938. Household income levels show a median of $90,357. The poverty rate stands at 7.84%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.

Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.

Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.

Name	Median	Mean
Households	$90,357	$82,538
Families	$90,000	$85,030
Married Families	$90,000	-
Non Families	-	$76,309

$40,938

Average Income

$90,357

Median Household Income

7.84%

Poverty Rate