Closer than most people guess: Australia (7,706,009 km² km²) is only about 28%% larger than Canada (9,872,102 km² km²).
Australia sits in Oceania, Canada in North America. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 1.3×.
The old map muddied it further: Mercator inflates Australia about 1.2× and Canada about 4.1×, so on a Mercator-style map this pair appears 4.3× apart instead of the true 1.3×.
Australia fits 1× into Canada.