What is a census tract number?

A census tract number is a numerical code, up to six digits long, that identifies a particular land area in the United States. Census tract numbers efficiently keep track of the many census tracts in the U.S. Census database.

A census tract number consists of a one- to four-digit number, sometimes followed by a decimal point and a two-digit suffix. Census tract numbers can be converted to census codes by removing the decimal if it is present. These numbers are used as unique identifiers of census tracts.

A single census tract is about the size of a neighborhood. They are defined by the populations they contain, although their boundaries are mapped to a geographical area.