A silverback gorilla typically weighs between 135 to 195 kilograms (300 to 430 pounds) and stands about 1.5 to 1.8 meters (4 feet 11 inches to 5 feet 11 inches) tall. Their arm span ranges from approximately 2.3 to 2.6 meters (7 feet 7 inches to 8 feet 6 inches)
. Some large individuals have been recorded at heights up to 1.95 meters (6 feet 5 inches) and weights up to 267 kilograms (589 pounds)
. Silverbacks are much larger and stronger than females, with an adult male being at least seven to eighteen times stronger than an average adult man
. The name "silverback" comes from the distinctive grayish or silver hair on their backs that develops as they mature around 12 to 13 years of age
