Adult Golden eagles range widely in size across their range. The largest races comprise the largest eagles of the genus Aquila. Length may vary from 26 to 40 incjes, wingspan can range from 59 to 95 incjes, and weight is from 5.5 to 15.4 pounds.

The plumage colors range from black-brown to dark brown, with a striking golden-buff crown and nape, which give the bird its name. The juveniles resemble the adults, but have a duller, more mottled appearance. Also, they have a white-banded tail and a white patch at the carpal joint that gradually disappears with every molt, until full adult plumage is reached in the fifth year.