A baby’s weight at birth is about 3.25kg, and the formula for calculating this is different for each age group due to the different rates of growth and development.
Within 1 week after birth, due to insufficient milk intake, water loss, fetal discharge, there may be a temporary weight loss, or physiological weight loss, about 3 ~ 4 days after birth to reach the lowest point, the decline range of 3% ~ 9%, and then gradually rebound, to the 7th to 10th day after birth should be restored to the weight of the birth.
The weight of a baby between 3 and 12 months of age (kg) = [age (months) + 9]/2. The weight of a child between 1 and 6 years of age (kg) = age (years) × 2 + 8. The weight of a child between 7 and 12 years of age (kg) = [age (years) × 7 – 5]/2.
Body weight is the total weight of each organ, system, and body fluid. Among them, bones, muscles, internal organs, body fat and body fluids are the main components. Because body fat and body fluids are highly variable, body weight is the most fluctuating of the physical growth indicators. Weight is easy to measure accurately and is the most readily available indicator of a child’s growth and nutritional status.
If your baby’s weight is abnormal, it is advisable to consult a nutritionist or pediatrician for early intervention.