Sex of person

Status: This was the departmental standard from January 25, 2018 to September 30, 2021.


Sex refers to sex assigned at birth. Sex is typically assigned based on a person's reproductive system and other physical characteristics.

Person refers to an individual and is the unit of analysis for most social statistics programs.


Sex and gender refer to two different concepts. Caution should be exercised when comparing counts for sex with those for gender. For example, female sex is not the same as female gender.

The variable 'Gender of person' and the 'Classification of gender' are expected to be used by most social statistics programs. The variable 'Sex of person' and the 'Classification of sex' are to be used where information on sex at birth is needed, for example for some demographic and health indicators.

Conformity to relevant internationally recognized standards

This standard includes more detailed and specific information than the recommendations for censuses contained in the United Nations' ''Principles and Recommendations for Population and Housing Censuses, Revision 3'', 2017. The United Nations document does not state the categories in the definition of sex nor does it specify whether sex refers to sex at birth.

The "Conference of European Statisticians Recommendations for the 2020 Censuses of Population and Housing" (2015) recognizes that some countries have started using sex categories in addition to 'male and female'. The option of a third category for sex is provided in the classification variant of sex in the Canadian standard. The Conference of European Statisticians caution that issues related to data collection and residual disclosure should be considered when using a classification with a third category for sex:

''It is known that a small proportional error occurs in reporting or coding large response categories (such as 'male' or 'female') but that these can nevertheless be larger than the number of correctly captured responses for a rare category (such as a 'third' sex). Even among the sub-group of particular interest, response patterns may be particularly sensitive to question wording. It is strongly recommended, therefore, that countries should undertake a rigorous testing programme before attempting to collect such information in the census. Furthermore, it should be noted that including such categories in outputs imposes risk to statistical disclosure since the relevant numbers are likely to be very small, particularly when cross-classified with other census variables.''

ISO/IEC 5218:2004 standard ''Information technology - Codes for the representation of human sexes'' specifies a uniform representation of human sexes for the interchange of information. It recognizes two sexes (male and female), consistent with the 'Classification of sex' presented in the Canadian standard. Although the ISO/IEC standard provides numeric codes, it states that these codes do not supplant national standards for codes derived from the names of sexes.

The Statistics Data and Metadata eXchange (SDMX) Statistical Working Group guidelines CL_SEX, Code list for Sex, Version 2.1 - 15/6/2017, recognizes two sexes and provides alphabetic codes for these: 'M' for Male and 'F' for Female. These classes and codes are consistent with the 'Classification of sex' presented in this standard.

Similar to the World Health Organization's 'Gender, equity and human rights, Glossary of terms and tools', this standard refers to sex assigned based on physical characteristics. While the World Health Organization indicates that such characteristics are used to define 'male' and 'female', this standard additionally provides a classification variant with three categories ('male', 'female' and 'intersex').


Additional information


Relation to previous version

  • Sex at birth of person October 01, 2021 to current

    The name of the concept has been changed from 'sex' to 'sex at birth', and the definitions in the categories of both classifications have been modified.

  • Sex of person January 25, 2018 to September 30, 2021

    This standard updates the definition by specifying that sex refers to sex at birth typically assigned based on a person's reproductive system and other physical characteristics. This standard also provides a classification variant of sex that recognizes the 'intersex' category. Alpha codes are provided for categories in both classifications presented in this standard.

  • Sex of person May 22, 2007 to January 24, 2018

    This was the departmental standard from May 22, 2007 to January 24, 2018.

Date modified: