Australia and continental US are about the same size.
Australia is 7.7 million sq. km. The continental US is 8.0 sq km.
If you add in Alaska and Hawaii the US jumps to 10 sq km.
Australia is the 6th largest country in the world. The US is number 4.
Australia is the smallest continent in the world, but is also the largest island.
I don't know if you can be a continent and island at the same time. That is what google said. Of course it is alway correct. :-).