The normal weight of a 4-month-old baby is around 5.25kg-10.39kg for male babies and 4.93kg-9.66kg for female babies; and the weight at birth, feeding situation, genetics and other factors will normalize the weight and there are individual differences. The normal weight of a 4-month-old baby boy is usually around 5.25kg-10.39kg, and the normal weight of a baby girl is around 4.93kg-9.66kg. Every baby’s weight at birth is different, for example, some babies are heavier at birth, so their weight at around 4 months of age will be heavier, while some babies are lighter at birth, so their weight at around 4 months of age will be lighter, so as long as they are within the normal range, there is no need to worry too much. After the birth of each baby feeding situation is different, their own growth and development is different, so the weight will be different, generally if the baby after birth feeding situation is good, the baby’s ability to absorb better, the baby’s growth and development will be faster, so the weight will also be heavy. Genetic factor is also one of the reasons affecting the baby’s weight, if both parents are heavier, the baby’s weight may also be on the heavy side. Generally speaking, if the baby’s weight is within the normal range, and the baby’s diet, mental state and bowel movement are normal, there is no need to worry too much. If you find that your baby’s weight gain is too slow, and your baby’s mental state, diet and bowel movements are not normal, we recommend that you go to the hospital and follow the doctor’s instructions to adopt the appropriate solutions.