Distribution of U.S. households by size 1970-2021

In 2021, 35.03 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 2020, 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 2019. 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.

Distribution of households in the United States from 1970 to 2021, by household size

Characteristic	One person	Two persons	Three persons	Four persons	Five persons	Six persons	Seven persons or more
2021	28.45%	35.03%	15.03%	12.39%	5.83%	2.03%	1.24%
2020	28.18%	34.83%	15.05%	12.66%	5.8%	2.27%	1.2%
2019	28.37%	34.51%	15.07%	12.76%	5.78%	2.26%	1.25%
2018	28.01%	34.52%	15.15%	12.91%	5.83%	2.23%	1.34%
2017	27.92%	34.47%	15.46%	12.84%	5.8%	2.21%	1.28%
2016	28.13%	34.01%	15.44%	12.93%	6%	2.24%	1.27%
2015	27.98%	33.61%	15.5%	13.21%	6.03%	2.26%	1.39%
2014	27.74%	33.75%	15.72%	13.18%	6.05%	2.25%	1.31%
2013	27.41%	33.89%	15.75%	13.36%	6.06%	2.23%	1.29%
2012	27.4%	33.8%	15.89%	13.25%	6%	2.25%	1.3%
2010	27%	34%	16%	14%	6%	2%	1%
2009	27%	33%	16%	14%	6%	2%	1%
2005	27%	33%	16%	14%	6%	2%	1%
2000	26%	33%	16%	15%	7%	2%	1%
1995	25%	32%	17%	15%	7%	2%	1%
1990	25%	32%	17%	16%	7%	2%	1%
1985	24%	32%	18%	16%	7%	3%	2%
1980	23%	31%	18%	16%	8%	3%	2%
1975	20%	31%	17%	16%	9%	4%	4%
1970	17%	29%	17%	16%	10%	6%	5%