Africa is the world's second-largest and second-most-populous continent after Asia. With 54 recognised countries and at about 30.3 million km², including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area. With 1.4 billion people as of 2021, it accounts for about 18% of the world's human population. It has the average youngest population with a median age of 19 years, and it's projected that 1 out of 5 people living in the world by 2050 will be African.