Background: Census Metropolitan Areas and Census Agglomerations

Census metropolitan areas (CMA) and census agglomerations (CA) are defined and maintained by Statistics Canada for statistical purposes in accordance with a set of published standards and delineation methodology.  Statistics Canada revisits its standards to ensure the continued relevancy of key concepts. 

A CMA or a CA is formed by one or more adjacent municipalities centred on a large core area with a high population density.  A CMA must have a total population of at least 100,000 of which 50,000 or more live in the core area.  A CA must have a core area population of at least 10,000.  To be included in the CMA or CA, other adjacent municipalities must have a high degree of integration with the central core area, as measured by commuting flows derived from census place of work data.

To define a CMA or CA, Statistics Canada begins with a large core area and then adds adjacent municipalities that have a high degree of integration with that core based on commuting flows derived from census place-of-work data. This approach combines criteria that are morphological (a densely populated core area) and functional (commuting flows between the cores and municipalities).

The last significant review of the methodology to define and delineate CMAs and CAs took place in the early seventies.  Since that time, a small number of incremental changes have been made to the methodology.¹

For more information, see the CMA/CA definitions.

Note

1. These changes are listed in the "changes prior to current census" section of the CMA and CA definition included at the end of this document.