Family size (for census family)

Status: This standard was approved as a departmental standard on May 26, 2021.


Family size refers to the number of persons in the family.

Census family is defined as a married couple and the children, if any, of either and/or both spouses; a couple living common law and the children, if any, of either and/or both partners; or a parent of any marital status in a one-parent family with at least one child living in the same dwelling and that child or those children. All members of a particular census family live in the same dwelling. Children may be biological or adopted children regardless of their age or marital status as long as they live in the dwelling and do not have their own married spouse, common-law partner or child living in the dwelling. Grandchildren living with their grandparent(s) but with no parents present also constitute a census family.

Conformity to relevant internationally recognized standards

This standard is compatible with the "Conference of European Statisticians Recommendations for the 2020 Censuses of Population and Housing", 2015 which recommended that family nuclei should be classified by size according to the total number of resident members of the family.


  • 'Number of persons (two or more)' is expressed as a number ranging from two to the maximum number on the file. October 22, 2007 to current

Relation to previous version

  • Family size (for census family) May 26, 2021 to current

    The definition of the statistical unit has been modified.

  • Family size of census family November 16, 2015 to May 25, 2021

    This is an update to 'Size of census family'. The concept has been renamed "Family size" and its definition has been simplified.

  • Size of census family October 22, 2007 to November 15, 2015

    This standard was replaced by the 'Family size of census family' as of November 16, 2015.

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