Which is the largest and deepest of Earth's five oceans?

The Pacific Ocean is the largest and deepest of Earth’s five oceans.

It covers about 165.25 million square kilometres, roughly one-third of Earth’s surface and more area than all the planet’s land combined. It stretches between Asia and Australia on the west and North and South America on the east, from the Arctic region toward Antarctica.

Its depth record comes from the Mariana Trench in the northwestern Pacific. Challenger Deep there reaches nearly 11,000 metres below sea level, making it the deepest known point on Earth. The ocean’s name reflects Ferdinand Magellan’s 1520 description of its relatively calm conditions after crossing the Pacific, although storms and powerful tropical cyclones are common.

A frequent mix-up is confusing the Pacific’s size with the Atlantic’s historical importance. The Atlantic is the second-largest ocean, while the Southern Ocean surrounds Antarctica and is not the largest despite its broad circumpolar extent.