The largest member of the canid family, the Gray Wolf may reach up to six feet (1.8m) in length   (including tail), and stands from thirty-three to thirty-eight inches (84 to 96.5cm) high at the shoulder. Average weight ranges from seventy to one hundred pounds (32 to 45kg); females are generally smaller than males. Size varies through its range; animals in colder climates have larger, bulkier bodies to help them conserve heat. As its  name implies, the Gray Wolf's coat appears in many shades of gray; it may also range from white to black with many combinations in between, including cream, tan, buff, sandy brown, and reddish.

The Red Wolf weighs approximately thirty-three to eighty pounds (15 to 36kg), stands about twenty-eight inches (71cm) at the shoulder, and measures an average of fifty-five inches (140cm) from tip of nose to end of tail. The coat of the Red Wolf shows considerable variation, from copper to cinnamon with deep gray-brown and black highlights. Fur on the underparts is generally lighter.