What is Earth's largest desert by total area?

Earth’s largest desert by total area is the Antarctic Desert.

Antarctica qualifies as a desert because deserts are defined by very low precipitation, not by heat or sand. Much of the continent receives little snowfall, especially in the extremely dry interior. The ice covering Antarctica therefore does not disqualify it from being a desert; it is a polar, or cold, desert.

The Antarctic Desert covers roughly 14 million square kilometres, making it larger than the Arctic Desert and far larger than the Sahara. About 98% of Antarctica is covered by a thick continental ice sheet, while the remainder consists mainly of exposed rock and other barren terrain. The continent’s Dry Valleys are among its most arid areas.

The Sahara is often called the world’s largest desert because it is the largest hot desert and the largest non-polar desert. That distinction causes the most common quiz mistake. Antarctica’s cold temperatures, sparse precipitation and enormous area give it the overall record, while the Sahara leads among hot deserts.