Distribution of households in the U.S., by household size 1970-2019

In 2019, 34.51 percent of all households in the United States were two person households. In 1970, this figure was at 29 percent.

Single households

Single mother households were the most common households with children under 18 years old in the United States in 2019, and North Dakota had the highest share of single-person households. Household size in the United States has decreased over the past century, due to customs and traditions changing. Families are typically more nuclear, whereas in the past, multigenerational households were more common. Furthermore, fertility rates have also decreased, meaning that women do not have as many children as they used to.

Average households in Utah

Out of all states in the U.S., Utah had the largest average household size in 2018. This predominately Mormon state has about three million inhabitants. The Church of the Latter-Day Saints, or Mormonism, plays a large role in Utah, and can contribute to the high birth rate and household size in Utah. The Church of Latter-Day Saints promotes having many children and tight-knit families. Furthermore, Utah has a relatively young population, due to Mormons typically marrying and starting large families younger than those in other states.