Week 16 old
Week 16 lands right around the 4-month checkup: more predictable feeds, longer sleep stretches, and a baby who's increasingly social and grabby. Here's what's typical.
In short
At 16 weeks, most babies take about 4-6 oz per feeding 5-6 times a day, sleep 14-16 hours total with 3-4 naps, and are smiling, cooing, and reaching for things around this age.
🍼 Feeding
Around 4-6 oz of breast milk or formula per feeding, roughly 5-6 times a day (about 24-32 oz total). Solids aren't recommended yet for most babies — most start closer to 6 months. Ask your pediatrician before starting.
😴 Sleep
About 14-16 hours total: roughly 10-12 hours overnight (often with 1-2 wakeups) plus 3-4 daytime naps. Wake windows tend to stretch to about 1.5-2.5 hours. Always back to sleep on a firm, flat surface with no loose bedding, pillows, or bumpers.
What's happening this week
- •Around now, many babies hold their head steady and push up on their forearms during tummy time.
- •Many 4-month-olds reach for and bat at toys, and bring their hands (and everything else) to their mouth.
- •Babies this age often laugh out loud, coo, and 'talk back' when you speak to them.
- •Some babies start showing signs of a so-called 4-month sleep regression as their sleep cycles mature — this is common and usually temporary.
Milestones to keep in mind
- ✓By the 4-month checkup, many babies smile to get your attention, coo, and turn toward voices — your pediatrician will check these in person.
- ✓Around this age, many babies hold their head steady without support and can push up to elbows during tummy time.
- ✓Many 4-month-olds bring hands to mouth and reach for toys, though the exact timing varies widely from baby to baby.
- ✓If your baby isn't smiling, making sounds, or following objects with their eyes by the 4-month visit, mention it to your pediatrician — ranges are wide, but it's worth a check.
Growth
💡 Tip for this week
If sleep suddenly gets choppier this week, it's often the normal 4-month shift in sleep cycles — keep a consistent, calming bedtime routine and put your baby down drowsy but awake rather than introducing new sleep crutches.
⚠️ When to call your pediatrician
Call your pediatrician for a fever of 100.4°F (38°C) or higher, fewer than 4-6 wet diapers a day, no weight gain, persistent poor feeding or vomiting, or if your baby isn't making eye contact, smiling, or holding their head up at all by the 4-month visit.
Frequently asked
How much should a 16-week-old eat?
Most 4-month-olds take about 4-6 oz of breast milk or formula 5-6 times a day, totaling roughly 24-32 oz in 24 hours. Babies vary, so follow your baby's hunger and fullness cues.
Is the 4-month sleep regression real?
Yes — around 4 months a baby's sleep cycles mature and become more adult-like, which can mean more night wakings for a few weeks. It's a normal developmental shift; a consistent routine and putting your baby down drowsy but awake usually help it pass.
Can I start solids at 16 weeks?
For most babies, solids are recommended closer to 6 months, once they can sit with support and hold their head steady. Some babies are ready a bit earlier, so check with your pediatrician before starting any solid foods.
Looking for the bigger picture? See the month 4 overview →
General guidance, not medical advice. Every baby develops at their own pace — talk to your pediatrician with any concerns.