Africa is "about 11.7 million square miles, which is really big—big enough to fit the United States, China, India, Japan, and much of Europe within its borders."
And here is a very large version of the map: http://static02.mediaite.com/geekosystem/uploads/2010/10/true-size-of-africa.jpg
The thing I found most interesting is that if you look at Greenland on a map, it appears massive. In actuality, it is only the 13th largest "country" in the world. Three countries in Africa - Sudan, Algeria, and Congo - are larger than Greenland but you would never guess that by looking at your average map.