3 month old babies usually need at least 5 of the 8 ounce baby bottles of formula or breast milk in a day.
As the baby gets to 6 months to 12 months of age and they are eating solid foods they usually only need 3 to 4 bottles of formula or breast milk during the day.
Your baby will usually let you know they are hungry by crying so always have some formula or breast milk ready in a bottle to warm up and feed them.
Your baby will let you know when they are not hungry so if you try to put a bottle up to their mouth or put the nipple in their mouth and they are not hungry and don't need fed they will push the bottles nipple out of their mouth.
So just make sure you're at least feeding your baby at 3 months old and earlier and beyond at least 3 to 5 bottles per day and try feeding them every hour or hour and half and if they refuse the bottle it means they are not hungry anymore.