Proportional representation electoral system

The electoral system used in local government elections in South Australia is the proportional representation electoral system, or PR for short.

Proportional representation is the term that describes a group of electoral systems used for elections in multi-member electorates to elect candidates who receive a set proportion of the vote. In Australia, these systems are classified into 3 categories.

  • List systems
  • Mixed-member proportional systems
  • Single transferable vote (STV) systems
In South Australia, the electoral system used is the STV type. Under STV electoral systems, each vote can be transferred between candidates in the order of the voter's preferences.

The proportional representation vote counting system is designed to ensure that vacant positions are allocated as nearly as possible in proportion to the votes received. It is assessed as a ‘fair’ system for counting votes but more complex than other counting systems, and may take longer to finalise.

A candidate is elected after obtaining a quota or proportion of the formal vote.

Calculating the quota

The quota is the number of votes a candidate needs to be certain of election.

The quota is calculated by dividing the total number of formal ballot papers in the count by one more than the number of vacancies available, adding one and ignoring any fractional remainder.

For example, if there were a total of 1,000 formal votes and 2 candidates to be elected, the quota would be:

Quota: (1,000 / (2 + 1)) + 1 = 334.333 = 334

PR count diagram

PR count simple

Proportional representation booklet

PR count processes and examples (PDF, 593KB)

Proportional representation - how we count the votes