"How many seats in total are in Parliament House?"

There are 76 senators  and 151 members of the House of Representatives.  These 227 positions are sometimes referred to as seats in parliament. To win a seat in the House of Representatives, you must be elected by the voters of your electorate. To win a seat in the Senate, you must be elected by the voters of your state or territory.

diagram to help explain How many seats in total are in Parliament House?