An 11-week-old typically drinks 24 to 32 ounces of breast milk or formula over a full day, spread across multiple feedings. The exact amount depends on your baby’s weight, and the simplest way to estimate it is to multiply your baby’s weight in pounds by 2.5. A 12-pound baby, for example, would need roughly 30 ounces in 24 hours.
How Much Per Feeding
At 11 weeks, most babies take about 4 to 6 ounces per bottle. This lines up with stomach capacity at this age, which falls in that same 4-to-6-ounce range. Trying to push beyond what your baby’s stomach can comfortably hold often leads to spit-up rather than extra nutrition.
If your baby is breastfed, you won’t be measuring ounces directly, but the same total daily volume applies. Breastfed babies at this age typically nurse 8 to 12 times in 24 hours, feeding every 2 to 4 hours. Each nursing session delivers a smaller volume than a bottle feeding, which is why the frequency is higher.
Using Your Baby’s Weight to Calculate Intake
The most reliable guideline comes from the American Academy of Pediatrics: babies need about 2.5 ounces of formula per pound of body weight per day. Here’s what that looks like for common weights at 11 weeks:
- 10 pounds: roughly 25 ounces per day
- 11 pounds: roughly 27.5 ounces per day
- 12 pounds: roughly 30 ounces per day
- 13 pounds: roughly 32.5 ounces per day
To turn that daily total into individual bottles, divide by the number of feedings. A 12-pound baby eating six times a day would get about 5 ounces per bottle. A baby who eats seven or eight times would take slightly less at each feeding but end up at the same daily total.
The 3-Month Growth Spurt
Right around 11 to 12 weeks, many babies hit a growth spurt. During these stretches, your baby may suddenly seem hungry all the time, wanting to eat as often as every 30 minutes and acting fussier than usual between feedings. This typically lasts only a few days.
If you’re breastfeeding, the increased demand is your baby’s way of signaling your body to produce more milk. Following your baby’s lead during these days, rather than trying to stick to a set schedule, helps your supply adjust naturally. For formula-fed babies, offering an extra ounce per bottle or adding a feeding during the day is a reasonable response. Once the growth spurt passes, your baby will likely settle back into a more predictable pattern.
How to Tell If Your Baby Is Getting Enough
Ounce counts are useful as a starting point, but your baby’s behavior is a better real-time guide. Hunger cues in the first few months include putting hands to the mouth, turning toward the breast or bottle (called rooting), lip smacking, and clenched fists. Crying is actually a late sign of hunger, so catching those earlier signals makes feedings smoother for both of you.
When your baby is full, the signals are just as clear: closing the mouth, turning away from the breast or bottle, and relaxing the hands. Pushing your baby to finish a bottle after these cues appear can override the natural sense of fullness, so it’s better to stop and offer more later if needed.
Beyond individual feedings, the best indicators that your baby is eating enough over time are steady weight gain (your pediatrician tracks this at checkups), six or more wet diapers per day, and a generally content mood between feedings. If your baby is hitting those markers, the exact ounce count matters less than you might think.
Breastfed vs. Formula-Fed Differences
Breastfed and formula-fed babies end up needing roughly the same total daily volume, but the feeding patterns look different. Breast milk is digested faster than formula, so breastfed babies tend to eat more frequently and take in smaller amounts per session. Formula-fed babies often space their feedings further apart and take larger volumes each time.
Neither pattern is better. What matters is the total intake over 24 hours and whether your baby is growing well. If you’re combining breast milk and formula, the same weight-based calculation still applies to the total across both sources.