According to the United States Census Bureau, the city has a total area of 2.6 square miles (6.8 km²), all of it land. The South Fork Catawba River borders Lowell on the north and the city is part of the Cramerton Watershed.
There were 1,085 households out of which 30.1% had children under the age of 18 living with them, 48.5% were married couples living together, 15.1% had a female householder with no husband present, and 31.0% were non-families. 26.4% of all households were made up of individuals and 12.1% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 2.88.
In the city the population was spread out with 23.0% under the age of 18, 7.4% from 18 to 24, 30.7% from 25 to 44, 22.0% from 45 to 64, and 16.9% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 85.4 males. For every 100 females age 18 and over, there were 81.6 males.
The median income for a household in the city was $33,586, and the median income for a family was $39,143. Males had a median income of $30,750 versus $24,063 for females. The per capita income for the city was $15,809. About 10.1% of families and 11.0% of the population were below the poverty line, including 15.4% of those under age 18 and 6.5% of those age 65 or over.
Lowell is in South Point Township.
Most of Lowell is in the attendance district for Lowell Elementary School. Southeastern parts of the city are in the attendance district for McAdenville Elementary School in McAdenville, and a small area in southwestern Lowell is in the attendance distinct for Gardner Park Elementary School in Gastonia. All of the city is in the attendance district for Holbrook Middle School.
High School age students attend Ashbrook High School in Gastonia, except for a small part of southeastern Lowell which is in the attendance district for South Point High School in Belmont.
Private schools in Lowell include the elementary school of Gaston Christian School. New middle school and high school facilities are currently under construction at the Lowell campus. In the meantime, the school has been renting facilities for the middle school and high school programs at the former campus of Sacred Heart College in Belmont since 1994.
Freight rail service is provided by the Norfolk Southern Railway. While Amtrak's passenger train also follows the Norfolk Southern main line, the nearest station is in Gastonia.