Feeding by age · Week 3
How much should a 3-week-old eat?
Last reviewed November 2026 against AAP, CDC, NHS and WHO guidance · Sources
Quick answer
Most 3-week-olds take about 2.5–3.5 oz (75–105 ml) of formula or expressed breast milk per feed, 7–10 times in 24 hours, for roughly 18–28 oz (540–840 ml) a day. Breastfed babies usually nurse 8–12 times a day. Week 3 is a classic growth-spurt window, so extra feeds are expected. Follow your baby's cues.
- Per feed
- 2.5–3.5 oz (75–105 ml)
- Feeds / 24h
- 7–10
- Daily formula
- 18–28 oz (540–840 ml)
On this page
- How much should a 3-week-old eat?
- What's happening at 3 weeks?
- How much formula does a 3-week-old need by weight?
- Sample 3-week-old feeding schedule
- What are hunger and fullness cues at 3 weeks?
- Is there a growth spurt at 3 weeks?
- What changes next week?
- When to call your pediatrician
- Questions parents ask
- Sources
How much should a 3-week-old eat?
| Formula | Breast milk | |
|---|---|---|
| Per feed | 2.5–3.5 oz (75–105 ml) | 2.5–3.5 oz (75–105 ml) per bottle of expressed milk; at the breast, your baby leads |
| Feeds in 24 hours | 7–10 | 8–12 breastfeeds |
| Daily total | 18–28 oz (540–840 ml) | Roughly 20–25 oz (600–750 ml) |
| Typical gap | Every 2–3 hours | Every 2–3 hours, closer during a spurt |
What's happening at 3 weeks?
Three weeks is a common time for a growth spurt. Feeding may look all over the place for a few days: shorter gaps, longer evening sessions and a bit more fussiness. It usually settles on its own.
Formula-fed babies often take 2.5–3.5 oz (75–105 ml) per feed now. If your baby drains every bottle and still roots, the AAP suggests offering about one extra ounce at a time rather than doubling up.
If you're breastfeeding and planning to introduce a bottle, La Leche League suggests waiting until breastfeeding is going well, ideally around three to four weeks.
How much formula does a 3-week-old need by weight?
The AAP's rule of thumb uses weight instead of age: about 2½ oz of formula per pound of body weight a day, and no more than about 32 oz (960 ml). In the UK, the NHS uses a similar guide of 150–200 ml per kg a day after the first week. Both are rough checks, not targets.
| Baby's weight | Per day (AAP, 2½ oz per lb) | Per feed at 7–10 feeds |
|---|---|---|
| 7.5 lb (3.4 kg) | About 19 oz (570 ml) | 2–2.5 oz (60–75 ml) |
| 8.5 lb (3.9 kg) | About 21.5 oz (645 ml) | 2–3 oz (60–90 ml) |
| 9.5 lb (4.3 kg) | About 24 oz (720 ml) | 2.5–3.5 oz (75–105 ml) |
Sample 3-week-old feeding schedule
| Time | What happens |
|---|---|
| 12:30 am | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 3:30 am | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 6:00 am | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 8:30 am | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 11:00 am | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 1:30 pm | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 4:00 pm | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 6:00 pm | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 7:30 pm | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
| 9:30 pm | Milk feed: 2.5–3.5 oz (75–105 ml) bottle, or a breastfeed |
During a growth spurt the gaps above may shrink to an hour or two for a few days. Follow your baby; the pattern comes back. Responsive feeding (offering milk when your baby shows hunger cues) matters more than the clock.
What are hunger and fullness cues at 3 weeks?
Hungry
- Rooting toward your chest or the bottle
- Fists to mouth and sucking sounds
- Puckering or smacking lips, clenched hands
- Fussing that builds; crying comes later
Full
- Closes mouth or pushes the nipple out with the tongue
- Turns head away from the breast or bottle
- Relaxed, open hands
- Fidgety or easily distracted once the edge is off
Is there a growth spurt at 3 weeks?
Growth spurt notes
Growth spurts around 2–3 weeks are common (USDA WIC). Expect a few days of extra feeds. Lots of wet diapers and a content baby between bunches are good signs that it's a spurt and not a supply problem.
What changes next week?
By week 4 many bottle-fed babies take 3–4 oz (90–120 ml) and start spacing feeds about 3–4 hours apart.
Read next: How much should a 4-week-old eat?
When to call your pediatrician
- A rectal temperature of 100.4°F (38°C) or higher in a baby 3 months or younger. The AAP says to call right away, even if your baby seems otherwise well.
- Fewer wet diapers than expected for their age (fewer than 6 a day from about day 5), or dark yellow urine.
- Very sleepy and hard to wake for feeds, floppy, or unusually quiet.
- Refusing feeds, or feeding poorly several times in a row.
- Signs of dehydration: dry mouth, no tears, or a sunken soft spot on the head.
- Forceful or green vomiting, or vomiting after most feeds.
- Red, black (after the first meconium poops) or white/pale gray poop.
- Yellow skin or eyes that spread or deepen, or any yellow color in the first 24 hours.
- Trouble breathing, blue or gray lips, or your baby is limp or very hard to wake: call 911 (or your local emergency number) now.
If something feels wrong, trust that feeling and call. You never need a reason beyond worry.
Questions parents ask
How much should a 3-week-old eat?
Typically 2.5–3.5 oz (75–105 ml) per bottle, about 7–10 times in 24 hours, for roughly 18–28 oz (540–840 ml) a day. Breastfed babies often still nurse 8–12 times a day.
Is my 3-week-old cluster feeding or not getting enough?
Cluster feeding usually happens in the evening and comes with plenty of wet diapers (6 or more a day) and steady weight gain. If diapers drop, weight stalls, or your baby seems hungry after nearly every feed, call your pediatrician for a weight check.
When can I give a breastfed baby a bottle?
La Leche League suggests waiting until a baby is about three to four weeks old and breastfeeding well, unless a bottle is needed sooner. Paced bottle feeding keeps bottles closer to the rhythm of the breast.
How do I know my 3-week-old is getting enough milk?
Look at diapers and growth more than ounces. Six or more wet diapers a day, regular poops, a baby who seems content after most feeds, and steady weight gain at checkups are the signs the AAP points to. If any of these slip, call your pediatrician.
Related guides
- Baby feeding chart by age: ounces and mlA baby feeding chart from week 1 to 12 months: ounces and ml per feed, feeds per day and daily totals for formula and breast milk, with sources.
- How to tell if your baby is getting enough breast milkSigns a breastfed baby is getting enough: wet and dirty diapers by day, weight gain, swallowing and contentment after feeds, plus the warning signs to act on.
- Cluster feeding: what's normal and how to get through itCluster feeding is feeds bunched together, often in the evening. When it happens, how long it lasts, how to tell it from low supply, and how to cope.
- Newborn feeding schedule: what a day really looks likeSample newborn feeding schedules for breastfed, formula-fed and combo-fed babies, from the first week to 3 months, with feeds per day and gaps between feeds.
- Paced bottle feeding, step by stepHow to pace a bottle feed: positioning, a horizontal bottle, breaks every few sucks and fullness cues. Works for breast milk and formula, and for every caregiver.
Free tools
Sources
Last reviewed November 2026. Numbers are ranges from these public health sources; 1 oz ≈ 30 ml.
- AAP · HealthyChildren.org: How Much Formula Does My Baby Need?
- USDA WIC Breastfeeding Support: Cluster Feeding and Growth Spurts
- La Leche League International: Bottles and Other Tools
- CDC: How Much and How Often to Breastfeed
- AAP · HealthyChildren.org: Fever and Your Baby
- AAP · HealthyChildren.org: How to Tell if Your Breastfed Baby is Getting Enough Milk
Feedoo Baby shares general information, not medical advice. Every baby is different. If you're worried about feeding, weight gain, diapers or your baby's health, call your pediatrician, midwife or health visitor.