|Motto: "In the Spirit of Town Government"|
|• Total||16.9 sq mi (43.8 km2)|
|• Land||16.6 sq mi (43.0 km2)|
|• Water||0.3 sq mi (0.9 km2)|
|Elevation||719 ft (219 m)|
|• Density||351.3/sq mi (135.6/km2)|
|Time zone||Central (CST) (UTC-6)|
|• Summer (DST)||CDT (UTC-5)|
|GNIS feature ID||1582881|
|Website||Town of Buchanan, Wisconsin|
According to the United States Census Bureau, the town has a total area of 16.9 square miles (43.8 km²), of which, 16.6 square miles (43.0 km²) of it is land and 0.3 square miles (0.9 km²) of it (2.01%) is water.
As of the census of 2000, there were 5,827 people, 1,846 households, and 1,583 families residing in the town. The population density was 351.3 people per square mile (135.6/km²). There were 1,868 housing units at an average density of 112.6 per square mile (43.5/km²). The racial makeup of the town was 98.30% White, 0.15% African American, 0.19% Native American, 0.79% Asian, 0.07% from other races, and 0.50% from two or more races. Hispanic or Latino of any race were 0.69% of the population.
There were 1,846 households out of which 52.8% had children under the age of 18 living with them, 80.6% were married couples living together, 3.3% had a female householder with no husband present, and 14.2% were non-families. 10.2% of all households were made up of individuals and 2.6% had someone living alone who was 65 years of age or older. The average household size was 3.13 and the average family size was 3.39.
In the town the population was spread out with 34.8% under the age of 18, 4.9% from 18 to 24, 38.1% from 25 to 44, 16.9% from 45 to 64, and 5.3% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 100.0 males. For every 100 females age 18 and over, there were 99.5 males.
The median income for a household in the town was $65,410, and the median income for a family was $68,405. Males had a median income of $46,482 versus $31,285 for females. The per capita income for the town was $22,729. About 0.4% of families and 1.2% of the population were below the poverty line, including 1.0% of those under age 18 and 1.9% of those age 65 or over.
Wisconsin International Raceway is located on County Road KK, East of Highway 55 in the town of Buchanan.