Europe dwarfs Nigeria: about 10,180,000 km² km² against 911,496 km² km². At true size Europe is about 11.2× larger — the whole of Nigeria fits into Europe roughly 11 times.
The old Mercator map treated both about equally (1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Nigeria fits 11× into Europe.