The total amount of milk a 4-month-old baby eats in a day is around 800-1000ml, with 5-6 feeds a day, each time the amount of milk is around 150-180ml. but every baby is different, and the amount of milk they eat will be different too. 4-month-old babies, if breastfeeding, the amount of food eaten every day is not easy to know, formula-fed babies can usually see the exact amount of milk, 150-180ml per feeding, 5-6 times a day, the total amount of milk a day is about 800-1000ml. Due to individual differences, the above figures are not absolute. Generally, as long as the baby’s mood and mental state are good after feeding, sleep is normal, normal bowel movements, and the baby’s weight elevation and growth is normal, it usually means that the milk quantity is sufficient and the feeding is adequate. 4-month-old baby has basically formed the regularity of breastfeeding, if the baby’s milk volume suddenly and significantly reduced, it is recommended to seek timely medical attention.