The physical sizes of elk vary greatly, depending on the species and gender. The three existing species of elk in America today - Tulle, Roosevelt and Rocky Mountain - vary greatly, and these differences should be noted, instead of lumping one standard weight for all bull elk or for all cow elk.
This is the smallest elk of the three. A mature Tulle Bull elk will weigh about 550 pounds, while a female will weigh about 350 pounds. A newborn calf weighs about 8 pounds at birth.
This is the largest of the elk species. A mature bull will weigh about a thousand pounds or more, while a cow will weigh about 600 pounds. A calf weighs about 18 pounds at birth.
Rocky Mountain Elk
This is the most numerous elk in America, and most standard elk weights tend to be taken from this species. A mature bull will weigh about 850 pounds, while a cow will weigh about 500 pounds. A calf weighs about 16 pounds at birth.
Of course, there are exceptions. One extraordinary Rocky Mountain Elk was weighed at 1,100 pounds. However, such an animal is a freak of nature. Most representative specimens in each subspecies will weigh within the parameters noted above.