According to the U.S. Census Bureau, the county has a total area of 259 square miles (670 km2), of which 29 square miles (75 km2) (11%) are covered by water;[5] two of Texas' most popular lakes are partially located in the county: Lake Tawakoni on the west and Lake Fork Reservoir on the east. It is the fourth-smallest county in Texas by land area and fifth smallest by total area.
U.S. Decennial Census[6] 1850–2010[7] 2010–2020[8]
Rains County, Texas – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.
As of the 2018 estimation,[11] there were 12,159 people, 4,333 households, and 2,680 families residing in the county. By 2020, there were 12,164 people residing in the county.[8] The population density was 53 people per square mile (20 people/km2). There were 5,411 housing units at an average density of 23 units per square mile (8.9/km2). Per the 2000 census, the racial makeup of the county was 93.6% White, 2.6% Black, 1.1% Native American, 1.1% Asian, 0.06% Pacific Islander, and 1.6% from two or more races; 9.2% of the population were Hispanic or Latino of any race.
There were 4,333 households, out of which 28.80% had children under the age of 18 living with them, 61.90% were married couples living together, 9.10% had a female householder with no husband present, and 25.90% were non-families. 22.30% of all households were made up of individuals, and 11.20% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 2.92.
In the county, the population was spread out, with 23.80% under the age of 18, 7.40% from 18 to 24, 25.10% from 25 to 44, 27.70% from 45 to 64, and 16.10% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 99.80 males. For every 100 females age 18 and over, there were 96.40 males.
The median income for a household in the county was $48,308 and the median income for a family was $40,329. Males had a median income of $31,983 versus $21,594 for females. The per capita income for the county was $23,936. About 11.40% of families and 17% of the population were below the poverty line, including 17.50% of those under age 18 and 14.10% of those age 65 or over.