There are twelve senators from each of the six States and, since 1975, two from each of the Northern Territory and the Australian Capital Territory, making in all 76 senators.

Senate Brief no. 1 Electing Australia's Senators

By voting at elections for the House of Representatives the people of each electoral division (also called an electorate or a constituency) select a person to represent them in the House. The House of Representatives currently has 150 members.

Infosheet no. 8 Elections for the House of Representatives

The essence of a parliamentary democracy is that citizens elect representatives to make laws on their behalf. General elections are held every three years to elect 150 members of the House of Representatives and 40 senators (half of the 72 state senators plus the four senators representing the two territories). The Constitution sets out the essential rules for calling general elections. It is compulsory for Australian citizens 18 years and over to vote.

Elections for the House of Representatives
Electing Australia's Senators
Elections: Constitutional Complexities and Consequences
The Constitution