How Tall Was T. rex?

If the Tyrannosaurus rex (T. rex)—the largest member of a group of theropod dinosaurs called tyrannosaurs—had stood upright, it would have been more than 6.5 meters (21 feet) tall. This would be about a meter higher than an adult male giraffe, which stands at about 5.5 meters (18 feet) tall. However, a T. rex’s usual posture was horizontal, with its body carried parallel to the ground and its tail held off the ground as a counterbalance. This posture was essential for maintaining stability and agility, especially when pursuing prey or navigating its environment. Its height at the hips would have been 3.6 to 3.9 meters (12 to 13 feet) approximately.

The T. rex was not only tall but also incredibly long and heavy. A large adult could measure more than 12 meters (about 39 feet) in length and weigh between 4,000 and 7,000 kg (about 9,000 to 15,000 pounds). The largest T. rex specimens known are “Sue”—which was discovered in South Dakota in 1990 and measures 12.8 meters (42 feet) long—and “Scotty”—which was found in Eastend, Saskatchewan, in 1991 and whose length and weight were estimated at 13 meters (42.7 feet) long and 8,870 kg (19,555 pounds), respectively.