There were 590 households out of which 39.5% had children under the age of 18 living with them, 76.9% were married couples living together, 7.3% had a female householder with no husband present, and 11.2% were non-families. 9.2% of all households were made up of individuals and 3.6% had someone living alone who was 65 years of age or older. The average household size was 3.03 and the average family size was 3.19.
In the city the population was spread out with 27.5% under the age of 18, 6.7% from 18 to 24, 29.9% from 25 to 44, 27.8% from 45 to 64, and 8.2% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 104.1 males. For every 100 females age 18 and over, there were 103.6 males.
The median income for a household in the city was $59,926, and the median income for a family was $61,563. Males had a median income of $41,532 versus $28,583 for females. The per capita income for the city was $22,610. About 3.0% of families and 5.4% of the population were below the poverty line, including 8.4% of those under age 18 and 11.5% of those age 65 or over.
Combine is served by Crandall Independent School District and by Dallas Independent School District. The students in the Crandall portion are zoned to Crandall Elementary School, Crandall Intermediate School, L.F. Raynes Middle School, and Crandall High School. Crandall Elementary is in Crandall. Crandall Intermediate and Raynes Middle are within the city of Crandall. Crandall High is in Crandall. The students in the Dallas portion are zoned to attend Seagoville schools, which are part of the Dallas Independent School District.