Initially it is best to feed your formula-fed baby on demand, or whenever they seem fussy because they are hungry. As a general rule of thumb, your formula-fed baby will likely take 2 to 3 ounces (60–90 mL) of formula per feeding and will usually eat every three to four hours on average during their first few weeks of life.
By the end of your baby’s first month, they will generally take up to at least 4 ounces (120 mL) per feeding, about every four hours.
By six months, your baby will typically consume 6 to 8 ounces (180–240 mL) at each of four or five feedings in twenty-four hours.
There are many factors that may affect the amount of formula your baby will consume. During growth spurts your baby may want more. During times of sickness, your baby may want less.
On average, your baby should take in about 2½ ounces (75 mL) of formula a day for every pound (453 g) of body weight.
Your baby will likely communicate with you regarding whether they are hungry or satisfied. If your baby seems restless or easily distracted during a feeding, they are most likely finished. If your baby finishes the bottle and continues sucking, they might still be hungry. Learning to read their signals around feeding can help you provide the right amount of formula for them.