Yeah, the area of Australia is smaller. But in my OP I said "edge to edge" by which I meant (ambiguously, sorry) west to east edges. People don't realise driving from west coast to east coast US is the same distance as Australia.

Area of mainland USA = 2.96M sq mi.

Area of mainland Australia = 2.93M sq mi.

I think this is the apples to apples comparison. Don't include Alaska or Tasmania, or Hawaii, which tend not to be what people are thinking of.

Australia is overlaid on a map of contiguous 48 states and DC, and that area is about 3.12M square miles. Yes, google is grand