The average length of a scarlet macaw is about 84 centimeters, with a significant portion being made up of its graduated tail. This species also has a larger percentage of tail compared to other large macaws. They typically weigh around 1 kilogram and have a plumage that is predominantly scarlet with light blue accents and gold iridescence. The central american subspecies is even larger, with an average length of 89 centimeters.