How much formula does a 9 month old need?

Quick Answer

At 9 months old, babies typically need around 24-32 ounces of formula per day, spread out over 4-5 feedings. The amount can vary based on the baby’s age, weight, and appetite. Speak to your pediatrician if you have concerns about your baby’s formula intake.

How Many Ounces of Formula Per Feeding?

The average 9 month old will take around 6-8 ounces of formula per feeding, with 4-5 feedings per day. However, this can vary significantly based on factors like:

  • Baby’s weight – Heavier babies may need up to 8 ounces per feeding. Lighter babies may only need 4-6 ounces.
  • Baby’s appetite – Some babies are heartier eaters and may want larger bottles. Other babies may prefer smaller, more frequent feeds.
  • Type of formula – Some formulas are more concentrated than others. Read label instructions for recommended serving sizes.
  • Time of day – Babies tend to be hungrier for morning/evening bottles and less interested in afternoon bottles.
  • Solid foods – As babies start solids around 6 months, they may need less formula at each feeding.

Watch your baby for cues that they are full or still hungry to determine the ideal amount for each feeding. At 9 months, babies should be feeding every 3-4 hours during the day.

Total Formula Needed Per Day

Most 9 month old babies need around 24-32 ounces of formula per day. However, this can vary significantly. Factors include:

  • Baby’s weight – Heavier babies need more formula than lighter babies. Consult your pediatrician.
  • Number of feedings – Babies who eat smaller bottles may need up to 5-6 feeds per day. Babies who eat larger bottles may only need 4 feeds.
  • Solid foods – As solids are introduced, formula needs may decrease. By 9 months, solids should provide a good portion of nutrition.
  • Water – Once solids are started, babies may need less formula if they are also drinking water.
  • Appetite – Some babies are heartier eaters and will want larger total daily volumes.

As a general guideline, here are typical daily formula needs by weight:

Baby’s Weight Typical Daily Formula Needs
15-20 lbs 24-28 ounces
20-25 lbs 28-32 ounces
25-30 lbs 32-36 ounces

Speak to your pediatrician if you are concerned your baby is not getting enough formula.

Signs Your Baby May Need More Formula

Some signs your 9 month old may need more formula include:

  • Seems hungry soon after eating
  • Sucks fingers/fists, smacks lips or turns head looking for more after feeding
  • Doesn’t sleep through the night and wakes up hungry
  • Cries during or right after feeds
  • Isn’t having the recommended number of wet/dirty diapers
  • Isn’t gaining weight appropriately

If you notice these cues, try offering baby an extra ounce or two at each feeding and see if it helps. Speak to your pediatrician if problems persist.

Signs Your Baby May Need Less Formula

Some signs your 9 month old may need less formula include:

  • Spits up or vomits regularly after feeding
  • Always leaves several ounces in the bottle after feeding
  • Takes less time to drink a bottle than before
  • Seems to lack interest or turns head away during feeding
  • Doesn’t wake up on usual feeding schedule
  • Gains weight rapidly or becomes overweight

If you notice these signs, try decreasing the bottle by 1-2 ounces at a time. Your baby may also need to be burped more frequently. Check with your doctor if problems continue.

Tips for Feeding a 9 Month Old

Here are some tips for bottle feeding a 9 month old:

  • Offer formula before solid foods – Milk should still be the primary source of nutrition at this age.
  • Feed on demand – Follow baby’s hunger cues rather than a rigid schedule.
  • Pace feedings – Go slowly, pausing often to prevent overeating.
  • Hold baby upright – This helps prevent ear infections and spitting up.
  • Burp frequently – Burp after every 1-2 ounces.
  • Use smaller bottles – 4-6 ounces reduces waste if baby doesn’t finish.
  • Watch for fullness cues – Don’t force baby to finish a bottle.
  • Experiment with nipple flow – Go up a nipple size if feedings are too slow.

Getting into a good feeding routine and responding to your baby’s hunger and fullness cues will help ensure they get the nutrition they need from formula at this age.

Supplementing with Solid Foods

Around 6 months, babies start supplementing formula with solid foods. By 9 months old:

  • Most babies get 1-2 solid meals per day plus 2-3 formula feeds.
  • Solid foods provide extra calories, nutrients, and opportunities to self-feed.
  • Introduce a wide variety of soft, mashed, chopped foods like cereals, purees, and finger foods.
  • Aim for iron-rich foods like meats, eggs, iron-fortified cereals.
  • Let baby explore self-feeding but be prepared for messes!

Talk to your pediatrician about introducing appropriate solids and making sure baby is developing the ability to chew, move solids to the back of their mouth, and swallow them safely. Solid foods should complement, not replace, formula at 9 months old.

Common Formula Concerns

When bottle feeding a 9 month old, some common concerns include:

Decreased Appetite and Formula Intake

It’s normal for appetite to fluctuate day to day. But if baby refuses bottles for several days or shows no interest in solids, see your pediatrician to rule out illness. Teething can also cause decreased appetite.

Not Sleeping Through the Night

Babies this age may wake at night if they aren’t getting enough formula to meet their nutritional needs. Try increasing the daytime bottle size slightly or adding an extra feeding. Check for signs of pain, illness or teething.

Spitting Up

Frequent spitting up or vomiting may indicate overfeeding, swallowing too much air or a formula intolerance. Try pace feeding, more frequent burping and keeping baby upright during and after feeds. Switch formulas if needed.

Gas and Constipation

Gas, fussiness and constipation can trouble a 9 month old as they adjust to solids. Limit gas-causing foods, keep them hydrated, massage their belly and bicycle their legs to relieve discomfort. Constipation may improve with extra water,prune juice or purees.


Loose stools can indicate an intolerance to a new food, viral illness or bacteria like Rotavirus. Avoid any new foods and stick to the BRAT diet until it improves: bananas, rice, applesauce, toast. Call your doctor if it persists more than 24 hours.


Increased physical activity and bouts of diarrhea or vomiting can lead to dehydration. Offer more frequent bottles and water breaks. Check for dry mouth, fewer wet diapers, fussiness, drowsiness and sunken eyes or fontanelle. Seek medical treatment if dehydration is suspected.

Introducing Whole Milk

The American Academy of Pediatrics recommends switching from formula to whole cow’s milk around 12 months of age. This provides key nutrients like fat, calcium and vitamin D for development.

To transition to whole milk:

  • Start by mixing whole milk with formula, gradually increasing the ratio of milk.
  • Aim for 16-24 ounces of whole milk per day, spread out over 3-4 servings.
  • Can be served cold from the fridge or warmed – test temperature before feeding.
  • Use a cup instead of a bottle to avoid tooth decay.
  • Limit milk to 24-32 ounces per day to leave room for solids.

If you have concerns about introducing whole milk or your baby has a family history of allergies, speak to your pediatrician first. Once on whole milk, limit or avoid sugary beverages like juice. Water should be offered in an open cup with meals.


Feeding a 9 month old the right amount of formula can be challenging as their needs change quickly. Watch your baby for hunger and fullness cues, be flexible with feeding times/amounts, and don’t stress if their appetite seems to change from day to day. Supplement formula with iron-rich solids. Speak to your pediatrician if you have concerns about your baby’s growth, nutrition or formula intake at this age. With patience and practice, you’ll find the right balance to keep your baby healthy, happy and growing on schedule!

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