Approximately how large is the Sahara Desert, the world’s largest hot desert?

The Sahara Desert covers approximately 9.2 million square kilometres. It is the largest hot desert on Earth, stretching across much of North Africa from the Atlantic Ocean to the Red Sea.

The Sahara is larger than the contiguous United States and occupies about 31% of Africa’s land area. Its boundaries are not sharply fixed because desert margins shift with rainfall and vegetation. The Sahel, a semi-arid belt south of the Sahara, forms a gradual transition rather than a clear border.

The Antarctic and Arctic deserts are larger overall, but they are polar deserts. This is why the Sahara is usually described specifically as the world’s largest hot desert. The Sahara also contains varied landscapes, including sand seas, gravel plains, rocky plateaus, mountains and depressions.

Its size has changed over geological time. During the African humid period, parts of the region supported lakes, grasslands and abundant wildlife, showing that today’s extremely dry landscape is not permanent.