Families in the United States
According to the U.S. Census Bureau, a family is a group of two people or more (one of whom is the householder) related by birth, marriage, or adoption and residing together; all such people (including related subfamily members) are considered as members of one family.
As of 2016, the U.S. Census Bureau counted about 82.18 million families in the United States. The average family consists of 3.14 persons in 2016, down from 3.7 in the sixties. This is reflected in the decrease of children in family households overall. In 1970, about 56 percent of all family households had children under the age of 18 living in the household. This percentage declined to 42.8 percent in 2015.
The average size of a family household varies greatly from state to state. The largest average families can be found in Hawaii and Utah, with an average of 3.69 and 3.67 members respectively. The smallest families can be found in North Dakota and Maine, with an average size of 2.94 and 2.89 members respectively.