The amount of milk for a three-day-old baby needs to be judged according to whether the baby is full-term or not, the feeding method and the baby’s weight. Normally it is around 30 to 80ml per feeding. If the baby is born at full term and weighs more than 3kg, it is usually recommended to breastfeed the baby, and the amount of milk for each feeding is usually 30-40ml. due to the baby’s fast gastric emptying speed, the baby may need to be fed at intervals of 3 hours every day, and may need to be fed more than 8 times a day, so the amount of milk for the baby every day is usually more than 240ml. If the baby who is just three days old is preterm and chooses to be artificially fed, the amount of milk that can be given is usually around 20 to 25 ml each time, depending on the baby’s weight, so that the amount of milk given per day may be between 160 and 200 ml. The amount of milk can be gradually increased within the acceptable range of the baby’s milk supply to help the baby absorb enough nutrients and promote physical development. The exact amount of milk for a baby that is just three days old should go to the hospital and under the guidance of a professional doctor, choose the appropriate feeding method as well as the amount of milk to feed.