The Apple website lists the MacPro 2009 as this:
Size and weight
Height: 20.1 inches (51.1 cm)
Width: 8.1 inches (20.6 cm)
Depth: 18.7 inches (47.5 cm)
Weight (standard configuration):
8-core: 41.2 pounds (18.7 kg)6
Quad-core: 39.9 pounds (18.1 kg)6
Here is the 2013: