Baby growth spurts.
Growth spurts most commonly land around 2–3 weeks, 6 weeks, 3 months, 6 months, and 9 months, and usually last 2 to 3 days — occasionally up to a week. Expect more feeding, more fussiness, and disrupted sleep, then a return to normal.
The calendar
Averages, not appointments. Babies have spurts off this schedule all the time, and some pass unnoticed.
2–3 weeks
Often the first one parents notice, and the one most likely to be mistaken for low milk supply. Feeding can become almost continuous in the evenings.
6 weeks
Frequently overlaps with the peak of evening fussiness, which makes it feel like the hardest week of the early period. It usually is not a coincidence — both are happening at once.
3 months
Often arrives alongside changes in sleep, so a spurt and a sleep regression can be tangled together.
6 months
Commonly coincides with the start of solids and with sitting up, so appetite and routine shift together.
9 months
Often lines up with crawling or pulling to stand, and with a nap transition.
12 months
Frequently accompanies walking. Appetite can swing noticeably in both directions around this age.
What a spurt looks
like.
- 1Feeding far more often, sometimes every hour
- 2Fussier and harder to settle than usual
- 3Sleep disrupted — more waking, or unusually long stretches
- 4Wanting to be held much more than normal
- 5Suddenly filling out clothes that fit last week
Cluster feeding and growth spurts are closely linked — a spurt is one of the most common reasons a baby suddenly starts feeding in clusters.
The supply worry, which is almost always wrong
The 2-to-3-week spurt is the single most common reason parents conclude their milk supply has failed. A baby who fed every three hours yesterday now wants feeding every 45 minutes, and the obvious conclusion is that there is not enough milk.
Frequent feeding during a spurt is how a breastfed baby signals for more, and supply generally responds within a few days. It is the mechanism working, not failing. If weight gain or wet diaper counts genuinely concern you, that is a conversation for a lactation consultant, health visitor, or pediatrician — not a chart.
Spurt or something else?
| What | How long | Telltale sign |
|---|---|---|
| Growth spurt | 2–3 days, up to a week | Hunger leads. Feeding frequency jumps first. |
| Sleep regression | 2–6 weeks | Sleep leads. Appetite is often unchanged. |
| Witching hour | Daily, for weeks | Same time each evening, and resists soothing. |
| Illness | Varies | Fever, unusual lethargy, or fewer wet diapers. Needs a call. |
Two days or two weeks? Your log knows.
A spurt passes in a few days; a regression does not. Told apart, they call for completely different responses — and a week of logged feeds and sleep makes the difference obvious at a glance.
Free on iPhone. No account, works offline.
Common questions
When do babies have growth spurts?
The commonly cited ages are around 2 to 3 weeks, 6 weeks, 3 months, 6 months, 9 months, and 12 months. These are averages rather than a schedule — plenty of babies have spurts at other times, or have them without their parents ever noticing.
How long does a baby growth spurt last?
Usually 2 to 3 days, though a spurt can stretch to about a week. Feeding and sleep generally return to their previous pattern once it passes.
What are the signs of a growth spurt?
The usual signs are a sudden increase in hunger and feeding frequency, more fussiness, and disrupted sleep — either waking more often or sleeping unusually heavily. Some parents also notice their baby suddenly outgrowing clothes or wanting to be held far more than usual.
Does a growth spurt mean my milk supply has dropped?
Usually not. Frequent feeding during a spurt is how a breastfed baby signals for more milk, and supply generally responds within a few days. Feeding more often during this period is the mechanism working as intended, not evidence that it has failed. If you are worried about weight gain or wet diapers, speak to a health visitor, lactation consultant, or pediatrician.
Is a growth spurt the same as a sleep regression?
No, though they often overlap. A growth spurt is a short burst of physical growth lasting a few days, driven by appetite. A sleep regression is a longer change in sleep patterns, usually tied to development, and can last weeks. The 3-month and 6-month points commonly feature both at once.
Should I feed on demand during a growth spurt?
Following your baby's hunger cues is the usual advice during a spurt, and feeding more frequently for a few days is expected. If you have specific concerns about intake, weight gain, or your baby's wellbeing, check with your pediatrician rather than working from a schedule.
Sources
- Pathways.org — what are baby growth spurts
Timing and signs, from a child development nonprofit.
- Cleveland Clinic — growth spurts
Clinical overview of growth spurt timing and duration.
- The Bump — baby growth spurt ages and signs
Summarises the AAP-cited spurt ages used in the calendar above.