Australia dwarfs Sudan: about 7,706,009 km² km² against 1,863,027 km² km². At true size Australia is about 4.1× larger — the whole of Sudan fits into Australia roughly 4 times.
Australia sits in Oceania, Sudan in Africa. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 4.1×.
The old Mercator map treated both about equally (1.2× vs 1.1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Sudan fits 4× into Australia.