Another difference is size. Lowland gorillas are 4 to 6 feet (1.2 to 1.8 meters) tall and weigh 150 to 400 lbs. (68 to 181 kilograms). Mountain gorillas are about the same height, though they tend to weigh a bit more. They are 4 to 6 feet tall and weigh 300 to 485 lbs.