Laysan albatrosses have blackish-brown backs and upper wings. The primary feathers have a flash of white. The under wing is also white, with black margins. There is a dark tail band that is visible during flight. Similar species are black-footed albatrosses (Phoebastria nigripes). They are distinguished because black-footed albatrosses are dark all over, including the under wings. The other similar North American albatross species, short-tailed albatrosses (Phoebastria albatrus), have a yellow wash on the head and neck.

Range mass: 1.9 to 3.1 kg.

Average mass: 2.4 kg.

Range length: 79 to 81 cm.

Range wingspan: 195 to 203 cm.

Average basal metabolic rate: 0.53 cm^3 oxygen/hour.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

Average basal metabolic rate: 7.462 W.