It is between 140 and 160 cm. The heaviest birds can weigh 14 kg. The plumage is entirely white, yellow and Black beak. The color of the bec distinguishes it from other species of swans; the yellow is very large and only the tip of the beak is black unlike Tundra Swans whose beak is predominantly black. The distinction between the whooper and Bewick Swan is more delicate, the yellow on the beak of the Swan of Bewick is generally restricted to the nasal region and presenting a rounded (in point at the whooper Swan). Birds feeding in Arctic tundra chalybeate waters often have reddish-tinged plumage.
It is the loudest of the swans and variations of her singing earned him the name whooper Swan.