Dear AGS Data Support,

What is the difference between a non-family household and a family household?

Family Matters in Maryland


Dear Matters,

Plain and simple, a non-family household is not a family household. Let us break that down further.

We break the population into two main groups, with households split –

  • Population in households
    • Family households
    • Non-Family Households
  • Population in group quarters

A household is one or more persons living in a private dwelling as opposed to living in group quarters. Group quarters typically means people in institutions, army barracks, and so forth.

A non-family household is one or more people living in a private dwelling who are not “related” persons. For example, two college students who rent an apartment off-campus are a non-family household.  A single person living in a house is also a non-family household. Four people who share a house but are not related are also a non-family household.

It becomes a family household if ANY two of the members are related by birth, marriage, or adoption – regardless of how many household members there are. So, if mom and child have a roommate to share expenses, it is a family household that also has an unrelated person.

This is increasingly a blurry topic – in the 2000 census, a same-sex couple could not be classified as a family unit. For the 2020 census, they are related by marriage and thus will be considered a family unit. The relatively common grandchild living with a single grandparent would be a non-family household, but if both grandparents are alive, it would be a family household.

For most purposes, the main distinction is that the vast majority of non-family households are actually singles.

By the numbers – (AGS’ 2020)

  • Total population: 330,218, 663
  • In group quarters: 8,091,501 (2.45%)
  • In family households: 265,126,932 (80.29%)
  • In non-family households: 57,000,230 (17.26%)


  • Total 129,263,948
  • Family 83,680,318 (64.74%)
  • Non-Family 45,583,630 (35.26%)

The average family household has 3.2 people, the average non-family household has 1.25 people.

We have generally found that most users do not make the distinction between the two household types – but because of the major size differences, they are generally quite different “consumer” units.