Which is the largest desert in the world by total area?

The correct answer is Antarctic Desert. The largest desert on Earth by total area is the Antarctic Polar Desert, covering the entire continent of Antarctica — approximately 14 million square kilometres. Despite being ice‑covered, it is a true desert due to its extremely low precipitation.

Defining a Desert: More Than Just Sand

• Desert Classification: A desert is defined not by temperature but by precipitation. Any region receiving less than 250 mm (10 inches) of annual precipitation qualifies. Antarctica's interior receives only about 50 mm of precipitation per year, almost all as snow, making it an extremely arid desert.
• Size Comparison: The Antarctic Desert dwarfs all hot deserts. The Sahara (approx. 9.2 million km²) is the largest hot desert, but still smaller. The Arctic Desert is second, and the Arabian Desert and Gobi Desert are much smaller still.
• Why It's a Desert: Despite being covered in ice, the air is extremely dry, and water is locked as solid ice, unavailable for liquid‑water based ecosystems. This meets the scientific definition of a polar desert.
• Other Options: The Sahara is often mistakenly thought of as the world's largest desert, but it is only the largest hot desert. The Arabian Desert (about 2.3 million km²) and the Gobi (1.3 million km²) are far smaller.

Therefore, the largest desert in the world by total area is the Antarctic Desert.