Legislative Council members are elected using a proportional representation voting system. The voting system is very similar to the system that is used to elect members to the Australian Senate. Candidates are elected in proportion to the overall level of support by the voters. The procedure for counting the Legislative Council votes is detailed in the Sixth Schedule of The Constitution Act 1902.

To be elected, a candidate must typically attain a quota of the votes. The quota is calculated as follows: 

For example: There are 21 members to be elected at the March 2007 State election and if there are some 3,800,000 formal votes, the quota to be elected will be 172,728. Any votes a candidate receives over the quota are known as surplus votes. Since it is impossible to tell which votes to use as surplus votes all of the elected candidates' votes are distributed according to their preferences. These distributed votes have a value less than one, calculated by dividing the number of surplus votes by the total number of votes the candidate received. Candidates can be elected by reaching a quota either on first preference votes or by receiving preferences transferred to them from other candidates. Candidates can also be elected if the remaining number of candidates in the count equals the number of vacant positions available.