Most babies start sleeping through the night around 6 months of age, though some reach this milestone as early as 3 to 4 months. “Sleeping through the night” in infant sleep terms means a stretch of five to eight hours without feeding, not the eight-plus hours adults typically expect. Getting there depends on your baby’s weight, feeding patterns, and ability to fall back asleep on their own after naturally waking between sleep cycles.
What “Sleeping Through the Night” Actually Means
Newborns have tiny stomachs and need to eat every few hours, so long stretches of sleep simply aren’t possible in the early weeks. Babies generally need to weigh at least 12 to 13 pounds before they can go six to eight hours without a feeding, according to Children’s Hospital of Philadelphia. For many babies, that threshold arrives somewhere between 3 and 4 months.
There’s another piece to the puzzle: circadian rhythm. Newborns can’t distinguish day from night. Their internal clock, the same system that tells adults when to feel sleepy and when to feel alert, takes weeks to develop. Until that system kicks in, your baby’s sleep will be scattered in short blocks around the clock. By about 3 months, most babies start consolidating more of their sleep into nighttime hours, which is the first sign that longer stretches are on the way.
How Babies Learn to Put Themselves Back to Sleep
Every human, adult or infant, wakes briefly between sleep cycles. The difference is that adults roll over and fall back asleep without remembering it. Babies have to learn that skill, and researchers call it self-soothing. At one month of age, infants put themselves back to sleep after only about 28% of their nighttime awakenings. By 12 months, that number rises to roughly 46%. Self-soothing behaviors typically start appearing between 4 and 6 months and gradually increase through the first birthday.
This is why “sleeping through the night” is somewhat misleading. Your baby will still wake up between cycles. The real milestone is when they can drift back to sleep without needing you to feed, rock, or hold them. Babies who fall asleep independently at bedtime (rather than while being fed or rocked) tend to develop this skill earlier, because they’ve practiced the transition from awake to asleep on their own.
A Realistic Month-by-Month Timeline
Every baby is different, but here’s a general picture of how sleep evolves:
- 0 to 2 months: Sleep comes in 2- to 4-hour blocks, day and night. Frequent feeding is normal and necessary.
- 3 to 4 months: Circadian rhythms start forming. Some babies begin sleeping one longer stretch of 4 to 6 hours at night. Many parents notice a temporary disruption around this time as sleep patterns reorganize.
- 4 to 6 months: Self-soothing skills start to emerge. Babies who’ve reached 12 to 13 pounds can physically go longer without eating. Many families see five- to six-hour stretches become consistent.
- 6 to 9 months: Most babies are capable of sleeping six to eight hours at a stretch. Night feedings become optional for many (though not all) babies at this stage.
- 9 to 12 months: Separation anxiety peaks around 9 months and can temporarily increase night waking. By 12 months, nearly half of all nighttime awakenings are resolved by the baby on their own.
How Feeding Method Affects Night Sleep
A common assumption is that formula-fed babies sleep longer because formula takes more time to digest. The reality is more nuanced. Research published in the journal Nutrients found that fully breastfed infants actually logged longer total night sleep and longer total sleep overall than formula-fed infants at multiple time points through the first two years. However, breastfed babies did wake more often during the night between 6 and 12 months.
In practical terms, this means breastfed babies may call for you more often in the night, but the total amount of sleep they get is not less. Partially breastfed babies (those getting both breast milk and formula) showed sleep patterns similar to fully breastfed babies. Switching to formula specifically to improve sleep is unlikely to make a significant difference in total rest for you or your baby.
Sleep Regressions and Setbacks
Just when you think you’ve turned a corner, your baby may start waking more again. These regressions typically last two to four weeks and are tied less to a specific age than to what your baby is going through at the time. Common triggers include growth spurts that increase hunger, learning a new physical skill like rolling or pulling up, illness, teething pain, changes in routine such as travel or starting daycare, and separation anxiety.
Separation anxiety is particularly disruptive around 9 months, when babies become keenly aware that you exist even when you leave the room. A baby who was sleeping beautifully may suddenly protest bedtime or cry out when they wake and find themselves alone. This is a normal developmental phase, not a sign that something has gone wrong with their sleep habits.
Sleep Training: What the Evidence Shows
Sleep training refers to structured approaches that help babies learn to fall asleep independently. The most studied methods involve gradually increasing the time before you respond to your baby’s cries at bedtime, giving them the opportunity to practice settling on their own. Research reviewed in Canadian Family Physician found that when parents use these approaches, infant sleep typically improves within one week.
Most pediatric sleep experts suggest waiting until at least 4 to 6 months to try any form of sleep training, since that’s when self-soothing abilities begin to develop. Before that age, babies often lack the neurological maturity to settle themselves consistently. Sleep training is a personal decision, and many families find their babies consolidate sleep on their own without formal training. There’s no single right approach.
Setting Up a Safe Sleep Environment
However your baby sleeps, the physical setup matters. The American Academy of Pediatrics recommends placing babies on their backs in their own sleep space, using a crib, bassinet, or portable play yard with a firm, flat mattress and a fitted sheet. Keep the sleep area free of loose blankets, pillows, stuffed animals, and crib bumpers. Avoid letting babies sleep on couches, armchairs, or in swings and car seats (unless actively traveling in a car). These guidelines apply whether your baby is sleeping for two hours or eight.
What You Can Do in the Meantime
While you’re waiting for longer stretches to arrive, a few habits can help your baby’s internal clock develop on schedule. Expose your baby to natural light during the day and keep nighttime feedings dim and quiet. Establish a short, consistent bedtime routine so your baby starts to associate certain cues with sleep. When possible, put your baby down drowsy but still awake, giving them a chance to practice the transition to sleep on their own.
If your baby is older than 6 months, gaining weight normally, and still waking multiple times a night, it’s worth considering whether a sleep association (like needing to be rocked or nursed to sleep) is the primary driver. Babies who rely on a parent’s help to fall asleep at bedtime will almost always need that same help when they wake between cycles at 2 a.m. Shifting that one habit, falling asleep independently at bedtime, is often the single most effective change families make.