The average weight of a calf at birth is 63.6 pounds for females. Male calves weigh about 5 percent more at birth. The size of the heifer, temperature and maternal nutrition all influence a calf's birth weight.
Many calves weigh 7 percent of their mother's weight. For example, a 1,000 pound heifer may give birth to a 70 pound calf. Cold temperatures result in higher birth weights, while higher temperatures result in lower birth weights. Caloric restriction of the heifer during gestation results in a lower birth weight only if calories are restricted to less than 70 percent of her daily needs.