Western Australia (Australia) is 2.6 times larger than South Australia (Australia).
Western Australia is a state occupying the entire western third of Australia. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Southern Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east. Wikipedia
South Australia is a state in the southern central part of Australia. It covers some of the most arid parts of the continent. With a total land area of 983,482 square kilometres, it is the fourth largest of Australia's states and territories. Wikipedia