The Gray Wolf weight and size can vary enormously worldwide.
Though both tend to increase proportionally with higher latitudes.
Generally speaking, height varies from 0.6–0.9 meters (26–36 inches) at the shoulder, and weight can range anywhere from 23–59 kilograms (50–130 pounds), making wolves the largest among all wild canids.
Although rarely encountered, extreme specimens reaching over 77 kg (170 lb) have been recorded in Alaska and Canada,
and the heaviest wild wolf on record, which was killed in Alaska in 1939, weighed 80 kg (175 lb).
The smallest wolves come from the Arabian Wolf subspecies, the females of which may weigh as little as 10 kg (22 lb) at maturity.
Females in a given population typically weigh about 20% less than their male counterparts.
Wolves can measure anywhere from 1.3–2 meters (4.5–6.5 feet) from nose to tail tip, with the tail itself accounting for approximately one quarter of overall body length.

Wolves are built for stamina, possessing features tailored for long-distance travel.
Narrow chests and powerful backs and legs contribute to the wolf's proficiency for efficient locomotion.
They are capable of covering several miles trotting at about a 10 km/h (6 mph) pace, though they have been known to reach speeds approaching 65 km/h (40 mph) during a chase (wolves only run fast when testing potential prey).
While sprinting thus, wolves can cover up to 5 meters (16 ft) per bound.

Wolves usually have blended pelages.

Wolf paws are able to traverse easily through a wide variety of terrains, especially snow.
There is a slight webbing between each toe, which allows wolves to move over snow more easily than comparatively hampered prey. Wolves are digitigrade, so the relative largeness of their feet helps to better distribute their weight on snowy surfaces.

The front paws are larger than the hind paws, and feature a fifth digit, a dewclaw, that is absent on hind paws. Bristled hairs and blunt claws enhance grip on slippery surfaces, and special blood vessels keep paw pads from freezing.
Furthermore, scent glands located between a wolf's toes leave trace chemical markers behind, thereby helping the wolf to effectively navigate over large expanses while concurrently keeping others informed of its whereabouts.

A wolf sometimes seems more massive than it actually is due to its bulky coat, which is made of two layers. The first layer consists of tough guard hairs designed to repel water and dirt.
The second is a dense, water-resistant undercoat that insulates. Wolves have distinct winter and summer pelages that alternate in spring and autumn. Females tend to keep their winter coats further into the spring than males.

Coloration varies greatly, and runs from gray to gray-brown, all the way through the canine spectrum of white, red, brown, and black. These colors tend to mix in many populations to form predominantly blended individuals, though it is certainly not uncommon for an individual or an entire population to be entirely one color (usually all black or all white).
A multicolor coat characteristically lacks any clear pattern other than it tends to be lighter on the animal's underside.
Fur color sometimes corresponds with a given wolf population's environment; for example, all-white wolves are much more common in areas with perennial snow cover.
Aging wolves acquire a grayish tint in their coats.

Adolescent wolf with golden-yellow eyes.

At birth, wolf pups tend to have darker fur and blue eyes that will change to a yellow-gold or orange color when the pups are 8–16 weeks old.
Though extremely unusual, it is possible for an adult wolf to retain its blue-colored eyes.

Wolves have stout, blocky muzzles that help distinguish them from coyotes and dogs. Wolves also differ in certain skull dimensions, having a smaller orbital angle, for example, than dogs (>53 degrees for dogs compared to <45 degrees for wolves) while possessing a comparatively larger brain capacity. Larger paw size, yellow eyes, longer legs, and bigger teeth further distinguish adult wolves from other canids, particularly dogs. Also, precaudal glands at the base of the tail are present in wolves but not in dogs.

Wolves and most larger dogs share identical dentition; the maxilla has six incisors, two canines, eight premolars, and four molars. The mandible has six incisors, two canines, eight premolars, and six molars.
The fourth upper premolars and first lower molars constitute the carnassial teeth, which are essential tools for shearing flesh. The long canine teeth are also important, in that they are designed to hold and subdue the prey. Powered by 1500 lb/sq. inch of pressure, a wolf's teeth are its main weapons as well as its primary tools. Therefore, any injury to the jaw line or teeth could devastate an individual, dooming it to starvation or incompetence.

All data on this page was taken from http://en.wikipedia.org/wiki/Wolf