Carmi is a city which is the county seat of White County, Illinois, United States, along the Little Wabash River, where the population was 5,240 at the 2010 census.
According to the 2010 census, Carmi has a total area of 2.531 square miles (6.56 km), of which 2.5 square miles (6.47 km) (or 98.78%) is land and 0.031 square miles (0.08 km) (or 1.22%) is water.
As of the census of 2000, there were 5,422 people, 2,390 households, and 1,477 families residing in the city. The population density was 2,187.7 people per square mile (844.1/km²). There were 2,667 housing units at an average density of 1,076.1/sq mi (415.2/km²). The racial makeup of the city was 98.30% White, 0.48% African American, 0.35% Native American, 0.24% Asian, 0.06% from other races, and 0.57% from two or more races. Hispanic or Latino of any race were 0.65% of the population.
There were 2,390 households out of which 23.8% had children under the age of 18 living with them, 49.7% were married couples living together, 9.2% had a female householder with no husband present, and 38.2% were non-families. 35.3% of all households were made up of individuals and 20.3% had someone living alone who was 65 years of age or older. The average household size was 2.16 and the average family size was 2.78.
In the city, the population was spread out with 20.4% under the age of 18, 8.2% from 18 to 24, 23.7% from 25 to 44, 21.7% from 45 to 64, and 25.9% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 84.4 males. For every 100 females age 18 and over, there were 81.7 males.
The median income for a household in the city was $25,667, and the median income for a family was $32,456. Males had a median income of $30,735 versus $16,693 for females. The per capita income for the city was $15,886. About 11.7% of families and 15.1% of the population were below the poverty line, including 21.4% of those under age 18 and 11.6% of those age 65 or over.