Household size

Living alone is the household form that most directly sets how many homes a given number of people need. A place whose population is flat but whose one-person share is rising is a place with rising housing demand, which is why this share is published beside population rather than folded into it.

It is also the household form most sensitive to the housing available. Small units and studios support it and family-sized units do not, so this share partly reflects what was built here rather than what people would choose — see studio and one-bedroom share.

One-person households sit at both ends of adult life: young adults early in their careers and older people living alone after a partner has died or moved into care. The share does not distinguish them, and two places with the same number can mean opposite things. Read alongside the age shares in this same drawer, that ambiguity mostly resolves.

Dormitories, barracks, nursing homes and other group quarters are excluded from both numerator and denominator, so a tract built around one of them reports this share on the comparatively few conventional households it has.

ACS 5-year windows overlap. Each vintage shares four of its five years with the vintage before it, so year-to-year movement reflects smoothed rolling estimates and turning points appear later than they occurred. In tracts with few households the estimate carries a wide margin of error.

Census tract boundaries were redrawn for the 2020 census. Estimates published on earlier boundaries are carried onto current ones before use, which bears most on the ten-year window — see geography.