What is the largest desert in the world?

The Antarctic Desert is the largest at about 14 million km². Because a desert is defined by low precipitation rather than heat, the polar ice sheet qualifies — it receives very little snowfall and is intensely arid despite being frozen.

Why are Antarctica and the Arctic counted as deserts?

A desert is any region receiving less than roughly 250 mm of precipitation a year. Both polar regions are extremely dry, so they meet the definition. They are classed as polar or cold deserts rather than hot deserts like the Sahara.

What is the largest hot desert?

The Sahara in North Africa is the largest hot desert at about 9.2 million km², roughly the size of the United States or China. It is the third-largest desert overall, behind the two polar deserts.

What is a coastal desert?

A coastal desert forms beside cold ocean currents that suppress rainfall, such as the Atacama in Chile and the Namib in Namibia. They can be among the driest places on Earth — parts of the Atacama go years without measurable rain — yet stay cool and foggy.

Are the desert areas exact?

No. Desert boundaries are defined by aridity, which shifts with climate, and different sources draw the edges differently. The figures here are approximate, widely cited values intended for comparison rather than precise survey measurements.

World Deserts Reference

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The world’s largest deserts

This reference ranks the largest deserts on Earth by area, from the polar ice deserts of Antarctica and the Arctic down through the great hot deserts and on to the cold and coastal deserts. Each entry shows the approximate area in square kilometres, the climate type, and the countries or regions it spans. Filter by name, type, or location to focus the list.

How it works

The key to this list is the definition of a desert: a region is a desert if it receives less than about 250 mm of precipitation per year, regardless of temperature. That is why the two largest deserts are frozen. The Antarctic and Arctic are polar deserts — bitterly cold, but so dry that they out-rank the Sahara by area.

Below the polar deserts the table groups regions into hot subtropical deserts (the Sahara, Arabian, Kalahari), cold winter deserts that freeze in winter (the Gobi, Patagonian, Great Basin), and coastal deserts formed beside cold ocean currents (the Atacama and Namib). The classification explains the climate, not just the size.

Notes and caveats

Polar deserts dwarf hot deserts: Antarctica alone is bigger than the Sahara and Arabian deserts combined.
Desert edges expand and contract with climate, so areas are inherently approximate and disputed between sources.
Semi-arid steppe and the cold deserts of Central Asia are sometimes counted or excluded depending on the rainfall threshold used.
The Atacama is often described as the driest non-polar place on Earth.