It is a large eagle with a length of 72–90 cm (28–35 in), a wingspan of 1.8–2.16 m (5.9–7.1 ft) and a weight of 2.45–4.55 kilograms (5.4–10.0 lb). Females are about a quarter larger than males. It closely resembles the Spanish imperial eagle, but has far less white to the "shoulder" and it is slightly larger.
Male and female imperial eagles form pairs at around 4 years of age, and remain in this monogamous pair for life. The Imperial eagle's large nest is called an eyrie, and is constructed from sticks at the top of a tall tree. The youngest imperial eagle hatchling is normally pecked to death or outcompeted for food by its older sibling. Originally a lowland species, in some areas the imperial eagle has been pushed to higher elevations by habitat loss and hunting. Imperial eagles feed mainly on mammals, birds and occasionally carrion (especially in winter.)