What is the world's largest desert by surface area?

Antarctica is the world’s largest desert by surface area, covering about 14 million square kilometres.

A desert is defined by very low precipitation, not by heat or sand. Antarctica receives little precipitation across most of its interior, so it is classified as a polar desert. The continent’s vast ice sheet can make this surprising, because many people use “desert” informally to mean a hot, sandy landscape.

The Sahara is the world’s largest hot desert, at roughly 9.2 million square kilometres. Antarctica is larger than the Sahara, but its dryness comes with extreme cold and persistent ice rather than dunes.

Antarctica is also Earth’s coldest, driest, and windiest continent. Its ice sheet contains approximately 90 percent of the planet’s freshwater ice, although the continent itself has almost no permanent native human population.