An 8-month-old typically needs about 24 ounces (720 mL) of formula per day, spread across four to five bottles. That number can range anywhere from 16 to 37 ounces depending on how much solid food your baby is eating, their size, and their appetite on any given day. The key at this age is that formula remains the primary source of nutrition, but solids are starting to play a bigger role.
Daily Formula Totals at 8 Months
At 8 months, your baby needs roughly 750 to 900 calories each day. About 400 to 500 of those calories should come from formula, which works out to around 24 ounces. A general rule of thumb that works across ages: babies need about 2.5 ounces of formula per pound of body weight per day. So an 18-pound baby would need roughly 45 ounces if they were only drinking formula, but since your 8-month-old is also eating solids, the actual formula amount is lower.
Each bottle at this age typically holds 4 to 8 ounces, and most babies take four to five bottles in a 24-hour period. Some days your baby will drain every bottle, and other days they’ll leave an ounce or two behind. Both are normal. The daily total matters more than any single feeding.
How Solids Change the Equation
Eight months is a transition period. Your baby is likely eating two to three small meals of solid food each day alongside their bottles. As solids increase, formula naturally decreases a bit. This is expected and healthy. The goal is to offer formula first at most feedings, then follow with solids, so your baby still gets the fat, protein, vitamins, and minerals that formula provides. Solids at this stage are supplementing formula, not replacing it.
Aim to feed your baby something every two to three hours, which comes out to about five or six eating occasions per day. That includes both meals and snacks. A typical day might look like a bottle in the morning, a small breakfast of pureed or soft foods, a mid-morning bottle, lunch with solids, an afternoon bottle, dinner with solids, and a bedtime bottle.
Reading Your Baby’s Hunger and Fullness Cues
No chart can tell you exactly what your individual baby needs on a Tuesday afternoon. Your baby’s own signals are the most reliable guide. Signs of hunger at this age include reaching or pointing toward food, opening their mouth when a spoon or bottle approaches, getting visibly excited at the sight of food, and using hand motions or sounds to tell you they want more.
Fullness looks different: pushing the bottle or food away, closing their mouth when you offer more, turning their head to the side, or using gestures and sounds that signal “I’m done.” Forcing the last ounce of a bottle when your baby is showing these signs can teach them to ignore their own satiety signals over time. If they consistently leave formula behind, that’s their body telling you the amount is right for them.
Night Feedings at 8 Months
Most formula-fed babies don’t need nighttime bottles after 6 months. Formula digests more slowly than breast milk, so an 8-month-old who is eating well during the day is unlikely to wake from genuine hunger. If your baby is still waking for a bottle, it’s often habit rather than nutritional need. You can gradually phase out night feeds by slowly reducing the amount in the nighttime bottle over a week or two, shifting those calories to daytime feedings instead.
When Intake Seems Too High or Too Low
There’s no single “right” number that applies to every baby, but the boundaries are worth knowing. If your baby is consistently drinking well over 32 ounces of formula per day and showing little interest in solids, that can crowd out the iron and other nutrients that solid foods provide. On the other end, a baby taking less than 16 ounces of formula and not making up the difference with solids may not be getting enough calories for steady growth.
A few things can temporarily change intake. Teething, mild illness, and developmental leaps often cause babies to drink less for a day or two. Growth spurts can send appetite in the other direction. Short-term fluctuations are rarely a concern. What matters is the trend over days and weeks, along with steady weight gain and plenty of wet diapers.
Water Alongside Formula
At 8 months, you can offer small amounts of water with meals. The CDC recommends 4 to 8 ounces of water per day for babies between 6 and 12 months. This is in addition to formula, not a replacement. A few sips from a cup at mealtimes helps your baby practice drinking and supports digestion of solid foods. Large amounts of water aren’t necessary and can fill up a small stomach, leaving less room for the formula and food that provide actual nutrition.