A very large eagle with a wingspan in the female reaching 2.2 metres. The female weighs up to 40% more than the male, otherwise the sexes are alike. The head, neck, underparts and all but base of the tail are snowy white, with the back, upperwings and base of the tail being grey.
The underwings are distinctive. The leading edge is white to off-white, with the trailing edge (primaries, secondaries and major coverts) being black. The cere is pale grey, the eyes brown, and the legs and feet, cream.
Juveniles are brown generally, with pale feather tips. The tail is white, shading to light brown.
The underwings are dark brown with a whitish ‘window’ across the bases of the primaries.
