Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. Algeria is Africa's largest country by area, and Nigeria is its largest by population.

The moon has a diameter of 1737 km and a surface area of 37.9 million sq km. The surface area is double the size of Russia or South America.