For geographic and demographic information on West Concord, which is part of Concord, please see the article West Concord, Massachusetts.
According to the United States Census Bureau, the town has a total area of 67.1 km² (25.9 mi²). 64.5 km² (24.9 mi²) of it is land and 2.5 km² (1.0 mi²) of it is water. The total area is 3.75% water.
As of the census of 2000, there are 16,993 people, 5,948 households, and 4,437 families residing in the town. The population density is 263.3/km² (682.0/mi²). There are 6,153 housing units at an average density of 95.3/km² (246.9/mi²). The racial makeup of the town is 91.64% White, 2.24% African American, 0.09% Native American, 2.90% Asian, 0.02% Pacific Islander, 2.12% from other races, and 0.99% from two or more races. 2.80% of the population are Hispanic or Latino of any race.
There are 5,948 households out of which 37.2% have children under the age of 18 living with them, 65.5% are married couples living together, 7.2% have a female householder with no husband present, and 25.4% are non-families. 22.0% of all households are made up of individuals and 10.4% have someone living alone who is 65 years of age or older. The average household size is 2.62 and the average family size is 3.08.
In the town the population is spread out with 25.1% under the age of 18, 4.2% from 18 to 24, 25.8% from 25 to 44, 28.4% from 45 to 64, and 16.5% who are 65 years of age or older. The median age is 42 years. For every 100 females there are 100.3 males. For every 100 females age 18 and over, there are 101.8 males.
The median income for a household in the town is $95,897, and the median income for a family is $115,839. Males have a median income of $82,374 versus $47,739 for females. The per capita income for the town is $51,477. 3.9% of the population and 2.1% of families are below the poverty line. Out of the total people living in poverty, 3.7% are under the age of 18 and 3.3% are 65 or older.