Divisions of the Australian House of Representatives

In Australia, electoral districts for the Australian House of Representatives are called divisions or more commonly referred to as electorates or seats. There are currently 150 single-member electorates for the Australian House of Representatives.

The Australian Electoral Commission determines from time to time the number of members to which each state and territory is entitled and the boundaries of each electorate, in a process known in Australia as redistribution.

Section 24 of the Constitution of Australia requires that the total number of members of the Australian House of Representatives shall be "as nearly as practicable" twice as many as the number of members of the Australian Senate.

Section 24 also requires that electorates be apportioned among the states in proportion to their respective populations; provided that each original state has at least 5 members in the House of Representatives, a provision that gives Tasmania higher representation than its population would justify.

The Commonwealth Electoral Act 1918 sets out further provisions. There are also two electorates in both the Australian Capital Territory and the Northern Territory.

Within each state and territory, electoral boundaries are redrawn from time to time. This takes place at least once every 7 years, or when the state's entitlement to the number of members of the House of Representatives changes. Boundaries are drawn by a Redistribution Committee, and apportionment within a state is on the basis of the number of enrolled voters rather than total residents or "population".

The number of enrolled voters in each division cannot vary by more than 10% from the average across a state or territory, nor can the number of voters vary by more than 3.5% from the average projected enrolment three-and-a-half years into the future. However, due to various reasons, larger seats like Fenner contain more than double the electors of smaller seats like Lingiari.

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