How Big Was Trex?
How Big Was Trex? Based on fossil specimens, scientists have determined that a Tyrannosaurus rex could be up to 40 feet long and 12 feet high. T. rex is estimated to have weighed between 11,000 and 15,500 pounds (5,000 and 7,000 kilograms) with skin and flesh on its huge bones. How big was the T.