Baby Growth Spurts: Signs, Timing and How to Cope

6 min read

Quick answer: A growth spurt is a short period of rapid growth when your baby's calorie needs rise, so they feed more, wake more and seem clingy or fussy. They cluster around 7–10 days, 2–3 weeks, 4–6 weeks, 3 months, 6 months and 9 months, and usually last a few days to a week. Feed on demand and expect routines to wobble.

What parents need to know

Just when you've settled into a feeding and sleeping rhythm, your baby suddenly seems hungry all the time, waking more, and more unsettled than usual. Sound familiar? You're almost certainly in the middle of a growth spurt.

Growth spurts are normal, temporary, and a great sign that your baby is developing well. Here's what you need to know.

Common ages	7–10 days, 2–3 weeks, 4–6 weeks, 3, 6, 9 months
Typical length	A few days to a week
Formula feeding	Increase volume, never concentration
Breastfeeding	Follow baby's lead and feed on demand

What is a growth spurt?

A growth spurt is a period of rapid physical growth during which your baby's calorie needs increase significantly. They tend to happen in bursts rather than as a steady progression, which is why they can feel disruptive when they arrive.

When do growth spurts happen?

While every baby is different, growth spurts tend to cluster around certain ages:

7–10 days
2–3 weeks
4–6 weeks
3 months
6 months
9 months

These are approximate. Your baby may have spurts at slightly different times, or you may not notice them all. A typical growth spurt lasts anywhere from a few days to a week.

Signs your baby is having a growth spurt

Increased hunger: Wanting to feed much more frequently than usual (cluster feeding in breastfed babies is very common during growth spurts)
More wakings at night
Fussiness and irritability
Increased clinginess
Longer or more naps (babies often sleep more during and after growth spurts as growth hormone is released during sleep)

What to do during a growth spurt

For breastfeeding mums

If your baby is cluster feeding, follow their lead. Feed on demand. This is not a sign that your milk supply is low: it's your baby's way of boosting supply to meet their new needs. Within a day or two, supply will adjust. Resist the urge to introduce formula unless advised by a healthcare professional, as this can affect your milk supply.

For formula-fed babies

You may find your baby needs more milk than usual. Don't increase concentration, just increase volume if your baby still seems hungry after a full feed. If you're unsure how much to increase, your health visitor can advise.

For everyone

Accept that routines may temporarily break down. This is normal
Rest as much as you can
Offer more comfort, cuddles, and carrying
Remember: it's temporary

Growth spurts vs. development leaps

Growth spurts are physical. "Wonder Week" leaps are cognitive development periods: times when your baby's brain is developing rapidly. They often overlap, which is why some periods feel particularly intense. Both are temporary, and both are positive signs of healthy development.

When to get help

If your baby seems unwell, do not put it down to a growth spurt. Trust your instincts. A growth spurt will not make a baby refuse feeds entirely.

Call 999 or go to A&E if your baby:

is under 3 months old and has a temperature of 38°C or higher, or is 3 to 6 months old and has a temperature of 39°C or higher
has a temperature below 36°C, or feels cold to touch or is shivery
has a weak, high-pitched or continuous cry
is difficult to wake, or cannot be woken, or is not responding like they normally do
has a high temperature and is not interested in feeding, or is not feeding and is not responding like they normally do
has not had a wet nappy in the past 12 hours
is breathing very fast or has difficulty breathing (they may make grunting noises or suck in their tummy when they breathe)
has blue, grey, pale or blotchy skin, lips or tongue (on brown or black skin this may be easier to see on the palms of the hands or soles of the feet), or skin that feels cold or clammy
has a rash that does not fade when you press a glass against it
is having a seizure (fit)

Call NHS 111 or contact your GP urgently if your baby:

is not feeding, or is feeding much less than normal, but is otherwise responding like they normally do and does not have a high temperature
is not their usual self and you are worried
shows signs of dehydration, such as fewer wet nappies, sunken eyes, or few or no tears when they cry
is 3 months or older and has had a temperature of 38°C or higher for more than 5 days

Speak to your health visitor if you are unsure whether your baby is feeding and growing as expected.

Frequently asked questions

How long does a baby growth spurt last?

A typical growth spurt lasts anywhere from a few days to a week. They tend to arrive in bursts rather than steadily, which is why they can feel disruptive.

Does cluster feeding mean my milk supply is low?

No. Cluster feeding is your baby's way of boosting supply to meet their new needs, and supply usually adjusts within a day or two. Avoid introducing formula unless a healthcare professional advises it.

Should I give my formula-fed baby more milk during a growth spurt?

Your baby may need more milk than usual. Increase the volume rather than the concentration if they still seem hungry after a full feed, and ask your health visitor if you're unsure.

When should I worry instead of assuming a growth spurt?

If your baby seems unwell, do not put it down to a growth spurt. Call 999 or go to A&E if they are under 3 months old with a temperature of 38°C or higher (39°C or higher at 3 to 6 months), have a weak, high-pitched or continuous cry, are difficult to wake, have not had a wet nappy in 12 hours, or show any of the other emergency signs listed in When to get help. Also call 999 if they have a high temperature and are not interested in feeding, or are not feeding and are not responding like they normally do. Call NHS 111 or contact your GP urgently if they are not feeding or are feeding much less than normal but are otherwise responding normally, show signs of dehydration, or are not their usual self and you are worried.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.