According to the Australian Government's GeoScience website, Australia's coastline (its border) is 35,877 km in length.
The distance is about 2,520 air miles from border to border.
The distance is around 3000 miles from Java to Australia.
Around 5000km.
Roughly 9000 miles.
Oman is around 4,700 miles from Australia.
It depends on 'where' among such borders. Distance between the northwestern border near Tijuana-San Diego down to the southwestern border with Guatemala is around 3220 kilometers (2000 miles). Distance between the northeastern Matamoros-Brownsville border and the southeastern border with Belize, there is a distance of 1232 kilometers (765 miles).
Tasmania has no border with South Australia.
Driving distance around Australia via Highway 1 is 9,010 miles. That is 14,500 kilometers. Highway 1 circumnavigates the Australian continent as a ring road.
If you mean the Rockingham that there is in Queensland, the distance from Sydney to Rockingham is around 2,258km. If you mean the Rockingham that there is in Western Australia, the distance from Sydney to Rockingham is around 3,985km.
Around 5500km/3500 miles.
The air distance in kilometers from Brisbane, Queensland, Australia, to Tweed Heads, New South Wales, on the border with Queensland, is 58 miles. That equals 93 kilometers or 50 nautical miles.
The flight distance from Thailand to Australia is approximately 3,640 miles or this can be converted to around 5,858 kilometres.