For a 45-day-old baby, the amount of milk is about 80m-120ml each time, some children eat more and can eat up to 150ml. Feeding every 2-3 hours is sufficient. The amount of milk for a child is influenced by many factors, such as the weight of the child at birth and the genetic factors of the family, which are closely related to the amount of milk for the child. If your child is in a good state of mind after feeding, has normal growth and development, and sleeps for a long time, and sleeps for about 3-4 hours after each feeding, it means that your child is getting enough milk and there is no need to worry too much. If the child is not getting enough milk, there is obvious crying, a decrease in urination and defecation, and a lag in growth and development. For children of this age, the amount of milk should be calculated based on body weight. Generally speaking, 150 ml/kg, the minimum should be 128 ml/kg.