According to the U.S. Census Bureau, the county has a total area of, of which is land and is water. The eastern third of Worth County, from west of State Route 33 heading east, is located in the Little River sub-basin of the Suwannee River basin. The northern third of the county is located in the MiddleFlint River sub-basin of the ACF River Basin. A narrow portion of the western edge of Worth County is located in the Lower Flint River sub-basin of the same ACF River basin. Finally, a portion of the southwest of the county, north of Doerun, is located in the Upper Ochlockonee River sub-basin of the larger Ochlockonee River basin.
As of the census of 2000, there were 21,967 people, 8,106 households, and 6,120 families living in the county. The population density was 39 people per square mile. There were 9,086 housing units at an average density of 16 per square mile. The racial makeup of the county was 68.69% White, 29.57% Black or African American, 0.36% Native American, 0.22% Asian, 0.01% Pacific Islander, 0.61% from other races, and 0.55% from two or more races. 1.09% of the population were Hispanic or Latino of any race. There were 8,106 households, out of which 36.3% had children under the age of 18 living with them, 55.7% were married couplesliving together, 15.7% had a female householder with no husband present, and 24.5% were non-families. 21.5% of all households were made up of individuals, and 9% had someone living alone who was 65 years of age or older. The average household size was 2.68 and the average family size was 3.12. In the county, the population was spread out, with 28.6% under the age of 18, 8.1% from 18 to 24, 27.50% from 25 to 44, 23.90% from 45 to 64, and 12% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 92.00 males. For every 100 females age 18 and over, there were 87.80 males. The median income for a household in the county was $32,384, and the median income for a family was $38,887. Males had a median income of $31,668 versus $20,950 for females. The per capita income for the county was $15,856. 18.50% of the population and 14.7% of families were below the poverty line. 25% of those under the age of 18 and 20.2% of those 65 and older were living below the poverty line.
2010 census
As of the 2010 United States Census, there were 21,679 people, 8,214 households, and 6,032 families living in the county. The population density was. There were 9,251 housing units at an average density of. The racial makeup of the county was 70.3% white, 27.6% black or African American, 0.3% Asian, 0.3% American Indian, 0.5% from other races, and 1.1% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 16.3% were American, 11.5% were Irish, 7.3% were German, and 6.9% were English. Of the 8,214 households, 35.1% had children under the age of 18 living with them, 50.8% were married couples living together, 17.1% had a female householder with no husband present, 26.6% were non-families, and 23.4% of all households were made up of individuals. The average household size was 2.62 and the average family size was 3.07. The median age was 39.7 years. The median income for a household in the county was $38,670 and the median income for a family was $46,791. Males had a median income of $35,829 versus $26,690 for females. The per capita income for the county was $18,348. About 15.6% of families and 20.8% of the population were below the poverty line, including 29.0% of those under age 18 and 16.7% of those age 65 or over.
