A weight chart for normal babies is available through the parenting and pregnancy experts at BabyCenter. The chart provides a range of normal weights for babies at birth, three, six, nine and 12 months of age, with continued height and weight ranges provided to 8 years.
Normal weights for babies at birth range from 6.7 to 7.1 pounds for boys and 6.5 to 7.8 pounds for girls, according to BabyCenter. The discrepancy continues as babies age, with boys averaging 13 to 15.2 pounds at three months, 16.2 to 18.8 pounds at six months and 18.2 to 21.1 pounds at nine months, as BabyCenter details. The ideal weight for girls is 11.8 to 14.0, 14.8 to 17.5 and 16.7 to 19.7 pounds at three, six and nine months, respectively.