Census in Australia

ABS House, the headquarters for the Australian Bureau of Statistics in Canberra
General information
Country	Australia
Date taken	9 August 2011 (2011-08-09)
Total population	21,507,717
Percent change	+8.3%
Annual percent change	+1.66%
Most populous state or territory	New South Wales – 6,917,658
Least populous state or territory	Cocos (Keeling) Islands – 550

The census in Australia, or officially, the Census of Population and Housing, is a descriptive count of everyone who is in Australia on one night, and of their dwellings. Participation in the census is compulsory, though answering some questions (such as religion) is optional.

The count is taken every five years and is managed by the Australian Bureau of Statistics (ABS). The first Australian census was held in 1911, on the night of 2 April (previous censuses being organised by the colonies) and subsequent censuses were held in 1921, 1933, 1947, 1954 and 1961. In 1961 the five-year period was introduced. Censuses are held on the second Tuesday of August. The most recent was held on 9 August 2016. The cost of the 2011 census was $440 million.

The census counts all people who are located within Australia and its external and internal territories other than Norfolk Island, with the exception of foreign diplomats and their families on the census night. A separate census of Norfolk Island has been conducted by the Norfolk Island Government every five years since 1981, and occurs on the same day as the Australian census. The census examines data such as age, gender, incomes, occupations, dwelling types and occupancy, transportation modes, ancestry, languages spoken, and optional questions, such as religion.

The Census and Statistics Act 1905 (Cth) led to the 1906 establishment of the Commonwealth Bureau of Census and Statistics (CBCS). The Bureau was renamed the Australian Bureau of Statistics in 1975.

The census is collected and published against geographic areas defined by the Australian Standard Geographical Classification (ASGC). The ASGC provides a set of geographic classifications (called structures) for the dissemination of all ABS statistics. In 2007 the ABS published an experimental set of spatial units called mesh blocks. The primary aim of mesh blocks is to provide a building block for constructing alternative and more relevant geographies. Only data on total persons and total dwellings is released at the mesh block level. Mesh blocks will form the basis of a new statistical geography, the Australian Statistical Geography Standard (ASGS).

The main structure of the ASGC includes the following geographic areas, from smallest to largest:

ASGC structures include: