Due to individual differences, each baby is different and drinks a different amount of milk, but in general, a 40-day-old baby will drink 80 to 120mL of milk at a time. Each baby’s stomach capacity, appetite size, and weight at birth are not exactly the same, so there are differences in the amount of milk consumed. For most babies, a 40-day-old baby will drink 80-120mL of milk every three to four hours, about six to seven times a day, or about 600-800mL a day. If the baby’s mental state is normal after eating milk, steady weight gain, no crying, bloating and diarrhea and other discomforts, it indicates that the baby’s milk intake is normal. If the baby’s milk intake is low and accompanied by crying, vomiting and other undesirable manifestations, you should consult a doctor for timely treatment.