Week 5 old
Week 5 of your baby's first year: feeding picks up, sleep starts to lengthen at night, and the first social smiles may be just around the corner. What to expect at 5 weeks old.
In short
At 5 weeks old, most babies are feeding 8 to 12 times a day, sleeping in short stretches around the clock, and starting to be more alert and responsive between feeds. Many are nearing their first real social smile, though there is a wide normal range for when it appears.
🍼 Feeding
Most 5-week-olds feed 8 to 12 times in 24 hours. Breastfed babies typically nurse every 2 to 3 hours, often with some cluster feeding in the evening. Formula-fed babies usually take about 3 to 4 ounces per feeding, roughly 24 to 32 ounces a day, on a slightly more spaced schedule. Appetite often surges around the 6-week growth spurt, so expect a day or two of extra-frequent feeding — it passes. Feed on cues like rooting, hand-to-mouth, and stirring rather than waiting for full crying.
😴 Sleep
Around 14 to 17 hours of sleep total per day, broken into short stretches with no real day-night pattern yet. Naps are frequent and irregular (often 4 or more), and wake windows are still very short — usually about an hour or less (often roughly 45 to 75 minutes), though this varies a lot from baby to baby and day to day. Some babies start having one slightly longer stretch at night, but this varies as well. Always place your baby on their back to sleep, on a firm flat surface, with no pillows, blankets, bumpers, or soft toys.
What's happening this week
- •Around this age, many babies become noticeably more alert, gazing at faces and high-contrast patterns for longer stretches.
- •By the 2-month checkup, the CDC notes many babies begin to smile socially in response to a familiar face or voice — for some, those first real smiles show up around now, and for others a little later.
- •Many babies start cooing and making early throaty vowel sounds in the coming weeks as they explore their voice.
- •Some babies briefly lift their head when on their tummy and can turn toward sounds, though strength and control vary widely from baby to baby.
- •Fussing and crying often peak around 6 weeks of age, then gradually ease — a normal developmental pattern, not a sign you are doing anything wrong.
Milestones to keep in mind
- ✓Watch for the first social smile in response to you — the CDC lists this as a 2-month checkpoint, so it is fine if it has not happened yet at 5 weeks.
- ✓Many babies are starting to follow a face or object briefly with their eyes around this age.
- ✓By the 2-month checkup, many babies briefly hold their head up and respond to loud sounds — these are ranges to watch for, not a weekly schedule.
- ✓Cooing and making sounds other than crying often begins over the next few weeks.
Growth
💡 Tip for this week
Build in short, low-key tummy time a few minutes at a stretch while your baby is awake and content, several times a day. It strengthens the neck and shoulders for the head control coming over the next couple of months. Always stay right there and supervise, and never let your baby sleep on their tummy.
⚠️ When to call your pediatrician
Call your pediatrician for: fewer than 5 to 6 wet diapers a day or signs of dehydration; any rectal temperature of 100.4°F (38°C) or higher — fever in a baby this young is an emergency, go in or call right away; poor feeding, unusual sleepiness, or trouble waking; no weight gain or weight loss; persistent vomiting (not normal spit-up), a bulging soft spot, fast or labored breathing, or a baby who seems inconsolable or unwell. Trust your instincts — when in doubt, call.
Frequently asked
Why is my 5-week-old suddenly feeding constantly?
A growth spurt commonly happens around 6 weeks, and many babies ramp up at 5 weeks heading into it. Cluster feeding for a day or two is normal and helps boost your milk supply if you are breastfeeding. As long as your baby is making plenty of wet diapers and seems satisfied after feeds, this usually passes within a few days. Mention it to your pediatrician if it is paired with poor weight gain or fewer wet diapers.
My baby isn't smiling yet at 5 weeks — is that okay?
Yes. The first true social smile is a 2-month CDC checkpoint, and there is a wide normal range for when it appears. Many babies smile socially somewhere between about 6 and 8 weeks, and some a bit later. Keep talking, making eye contact, and smiling at your baby. If there are no social smiles by the 2-month checkup, that is worth bringing up with your pediatrician.
How much should a 5-week-old sleep at night?
At 5 weeks, sleep is still spread across the day and night with no fixed pattern, totaling roughly 14 to 17 hours per day. Some babies begin having one longer stretch at night, but waking every 2 to 3 hours to feed is completely normal at this age. Keep night feeds calm and dim, and always put your baby down on their back on a firm, empty sleep surface.
Looking for the bigger picture? See the month 2 overview →
General guidance, not medical advice. Every baby develops at their own pace — talk to your pediatrician with any concerns.