In order to determine how much larger is Europe than Astralia you first take into account the surface area of each oh them.
Europe surface area = 10,18*10^6 km^2
Australia surace area = 7,692*10^6 km^2
Next, you calculate the quotient between the surface areas. This is going to give you how much largert is Europe, just as follow:
(10.18*10^6 km^2)/(7.692*10^6 km^2) = 1,323 km^2
Then, Europe is 1.323 larger than Australia.