Baby development standards are divided into weight growth standards and height growth standards. The weight gain standard is about 2.2-4.3kg for a normal full-term baby at birth. Weight gain is calculated as a multiple of birth weight at six months, about three times at one year of age, four times at two years of age, and four to six times at three years of age. weight up to six months of age is equal to birth weight plus months of age multiplied by 0.6 kg; 7-12 months weight is birth weight plus months of age multiplied by 0.6 kg; 2-7 years is age multiplied by 2 plus 8 kg. The rate of height growth is the fastest in the first year, with an average monthly growth of 2-2.5cm from 1-6 months; 1.5cm from 7-12 months. one week of age is about 25cm higher than at birth, which is about 1.5 times higher than at birth. Growth starts to slow down from the second year of life and grows about 10-12cm per year.