Baby weight chart: what’s the average baby weight and how to monitor weight gain

Understanding baby weight charts, how your baby grows in the first year and how to monitor growth can help you know what to expect

Baby weight chart as illustrated by newborn baby on weighing scales
(Image credit: Getty Images)

A baby weight chart is a great way to monitor your baby's weight gain; this is an important part of ensuring they’re developing as expected. 

However you choose to feed your baby - breastfeeding, formula feeding or combination feeding, their growth should be tracked. Though every baby is different, there are standardised charts that can help you and your healthcare team understand how your baby is growing.

So many parents feel anxious about monitoring baby weight gain, so that’s why we have put together this helpful guide to explain growth and weight charts and what to expect. After your baby is born, it can be normal and expected for them to lose some weight initially. The National Institute of Clinical Excellence (NICE) says it’s common for babies to lose weight in the earliest days of life (up to 10%), but most babies have regained their birth weight within 14-21 days.

Hannah Croft, an Internationally Board Certified Lactation Consultant (Infant Feeding Expert) explains, "In the UK, all families will be given a baby weight chart within their “red book”, the personal child health record (PCHR), to help them monitor the weight gain of their baby. These charts are based on an average baby’s growth, split by boys and girls, as they tend to grow at slightly different rates. They’re based on huge samples of healthy babies born at term (37 weeks). If your baby was born early (premature), you will use a different chart.”

Baby weight chart: what is it?

A baby weight chart is a standardised chart that shows the expected growth rate of your baby. It's a graph that allows you to track your baby’s weight in comparison with their age. Your baby will have separate charts for their weight, height and head circumference. These are printed in the personal child health record (PCHR), often known as the “red book”. All UK families will be given this important record within a few days of their baby’s birth. 

Each time they are weighed, your baby’s weight will be recorded on their weight chart. Eventually, over time, you can see a clear pattern of weight gain. Your health visitor or midwife will also record the weight in the back of the book, so you have a record. This will usually be recorded in kilograms and, if you wish, also in pounds and ounces. There is also a helpful measures conversion table included in the red book (PCHR) to help you understand their weight.

Jenny, 24 from Manchester, told us “I took my daughter, Sienna, to be weighed weekly because I was so worried she wasn’t gaining. Luckily my health visitor put my mind at rest and explained the weight charts to me. She said that they’re just one indication of how my daughter is doing and that really helped me to relax. Sienna was doing well, she was alert and meeting other developmental “milestones”, as expected.”

Baby weight chart: what’s the average weight for a newborn?


What is the average weight of a newborn baby?

The average weight for a baby at birth is around 7.5lbs; however, between 5.5 and 10.1bs is considered normal and healthy,' says Dr. Daniel Cichi, GP and medical advisor at Doctors 4 U. 'First babies are normally lighter than their siblings which come later and boys are usually slightly heavier than girls.' 

However, there are some factors that can impact a child’s weight gain before they’re even born because of their genetics and what happens in the womb. If you were a small baby, you are more likely to have a small baby.

Natalia, who has a boy and a girl, had babies weighing 5lbs 6 (boy) and 5lbs 1 (girl). She said, “I am quite short (5ft), and I was a small baby. My mum said I was only 5lbs at birth. So I wasn’t surprised when my children were both born little. My son is now almost 7 and amongst the shortest in his school year. However, he was never going to be a tall beanpole because of my height. Both my kids are perfectly healthy, just smaller than their friends.”

The World Health Organisation defines a low birth weight as less than 2500 grams (or 5.5 pounds). High birth weight (known as macrosomia) means a weight greater than 4,200 g (9 lb 4 oz). A normal weight (for a baby delivered after 37 weeks) is 2,500–4,200 g (5 lb 8 oz – 9 lb 4 oz).

This can be because a baby has been born prematurely or has struggled with growth in the womb (known as intrauterine growth restriction, or IUGR). This affects around 6% of UK births. According to the NHS, the developmental age of a premature baby is calculated from their original due date, not from the date they were born, until they reach 2 years old.

The birth weight of a newborn can also be impacted by:

What are percentile lines?

Each line shows where your baby is tracking, on average, compared to the rest of the population. Many parents can find this concept a little confusing. As an illustration, babies who are on the “75th centile” are larger than 75% of other babies of the same age. It doesn’t necessarily matter which centile your baby is tracking, as long as their growth is following the “trend” and continuing to follow that curved line.

All your baby's weight, height and head circumference charts also have “percentile” lines printed on them to help you understand where your baby is tracking compared with other boys or girls of the same age. These are based on huge samples of normally growing babies. 

Hannah Croft, Infant Feeding Specialist (IBCLC), explains: “Percentile lines are based on the average growth expected for a baby of that age. So they show you what to expect. Lots of parents think that a larger number is better (so being on the 75th percentile is better than the 25th), but that’s not the case at all. It’s about whether they roughly follow the line they’re on. Sometimes, babies can go up or down the lines a little if they’ve been ill or gone through a growth spurt. This isn’t always cause for concern, but if they move through one or two percentiles, this does indicate a problem which needs investigation. Seek help from your health visitor if this is happening or you have any other worries about your baby’s growth.”

Midwife Cathy Tabner has more: "All babies grow at different rates, and what is normal can vary a lot. The key thing to look for is continued growth. If your baby’s growth percentile alters by 2 percentiles or lines on the chart, this may trigger a referral for assessment and support by a clinician." 

Average baby weight each month in the first year

Important note: these figures are a useful guide and are dependent on many factors. If your baby is not following this pattern of growth, seek advice, but it is not necessarily an immediate cause for concern. So many factors can affect the growth of a child, from allergies to minor illnesses like coughs, colds and stomach bugs. The introduction of solid foods (weaning) around 6 months will also affect the growth of a child over this age, and all babies take to eating solid foods differently. For more information on nutrition for your baby in the first year, please see Start4Life.

  • Birth is around 7.2lbs for a girl and 7.6lbs for a boy
  • First month is 9.4lbs for a girl and 9.14lbs for a boy
  • Second month is 11.5lbs for a girl and 12.4lbs for a boy
  • Third month is 12.14lbs for a girl and 14.1lbs for a boy
  • Fourth month is 14.3lbs for a girl and 15.7lbs for a boy
  • Fifth month is 15.3lbs for a girl and 16.9lbs for a boy
  • Sixth month is 16.1 for a girl and 17.8lbs for a boy
  • Seventh month is 16.14lbs for a girl and 18.5lbs for a boy
  • Eighth month is 17.8lbs for a girl and 18.15lbs for a boy
  • Ninth month is 18.2lbs for a girl and 19.10lbs for a boy
  • Tenth month is 18.11lbs for a girl and 10.3lbs for a boy
  • Eleventh month is 19.4lbs for a girl and 20.12lbs for a boy
  • Twelfth month is 19.12lbs for a girl and 21.4lbs for a boy

Factors that affect a baby's birth weight

(Image credit: Future)

Laura, mum of 5, told us, “All my babies have been premature, but once they were out of NICU, they shot up their charts. Being born premature doesn’t always mean they will be small. My eldest boys are really tall now, and they tower over me. Keep a close eye on your baby’s weight, but try not to get obsessed. It’s really easy to get overly worried, especially if they were so little at birth. My midwives and health visitor really helped me understand what to expect and reassured me loads I was doing a great job with each one.”

What’s the average baby length? 

'The average length for a full-term baby at birth is 20 inches. However, between 18 and 22 inches is considered normal and healthy,' says Dr Cichi. Your baby’s length is sometimes another good indicator of how they are growing, as some babies are naturally longer and leaner than other, shorter babies. You might notice that their feet are straining at their babygrows, even if they still fit around the chest, shoulders and arms.

Mother of three, Naomi from Kent, says, “My third baby was so much bigger than his brother and sister. From birth, he didn’t fit in the same clothes they wore from birth. Even his feet were bigger, and we were so surprised by that. He never wore the pretty bunny slippers a friend bought us; we couldn’t get them on him. We ended up cutting the feet off some of his clothes so he could wear them a bit longer. It just goes to show how even babies from the same parents can be so different.”

At birth, the average head circumference is 33.9 cm for girls and 34.5 cm for boys (World Health Organisation). Your baby's head will grow at its fastest rate during the first 4 months after birth than at any other time due to rapid brain growth. From birth to roughly 8 weeks, there’s an incredible weekly growth of around 0.5cm. This slows down from 2 to 6 months when you can expect a growth of about 0.25cm. 

How often should my baby be weighed?

Baby weight chart: what’s the average weight for a newborn?


Your baby will be weighed in the first few hours after birth and then again on days five and 10. If your baby was born early (before 37 weeks) or needs help from a special care baby unit or neonatal intensive care unit, their weight will be monitored more often. 

Midwife Cathy Tabner says, "All babies lose weight in the week after birth and usually regain by two weeks, doubling their birth weight by four months in most cases. Any baby not feeding well or who has any issues of concern may be weighed more frequently."

The midwifery team will usually send someone to your home to weigh your baby and hand your care over to your Health Visitor if there are no concerns. A health visitor is a qualified nurse or midwife with extra training to support families with children up to 5. You can find contact information on your Health Visiting team from your local council.

Depending on your area, you may have access to baby weight clinics at Children's Centres or other locations nearby. Find your local SureStart clinic here.

The NHS recommends that your baby is weighed around once a month until they are six months old. Then, every two months until they are 12 months old and every three months after that.

"Physically looking at your baby and taking photos as well as noting their feeding patterns whilst watching them grow out of their clothing and nappies is another good indicator that they are growing and thriving," says Cathy. 

Is my baby putting on weight properly?

If you have concerns about your baby’s weight gain, it’s important to seek help quickly. Babies who are not gaining weight can find it hard to catch up as they are losing energy and that affects how effectively they feed. They might sometimes sleep more, too if they are conserving energy. If you have any concerns, you must seek support from your GP or Health Visitor or Midwife. Many weight gain concerns can be rectified quickly. 

If your baby is not gaining weight as expected, your health visitor may recommend your baby is weighed more often. They will give you support on breastfeeding, combination feeding or formula feeding your baby. 

Sarah, mum of two from Cambridge, told us “my second baby wasn’t gaining weight well at all and having to weigh him all the time caused me so much stress. Eventually we had to go into hospital to monitor what went in and what went out. The doctors were fantastic and really made me feel supported to breastfeed. It turned out he had a tongue tie, which a lactation consultant diagnosed. It wasn’t something the doctors had as much experience in as I was expecting, so I was so grateful for breastfeeding experts. After it was divided, the difference was almost instant. He’s a chunk now: we even skipped 9-12 month clothing sizes because he has some seriously cute leg rolls.”

Bottle feeding and baby weight

If you are bottle feeding your baby expressed milk or formula, it’s important to ensure that you are feeding them responsively. This means allowing your baby to take as much or as little as they want per feed. It can be tempting to want your baby to finish the bottle entirely, but responsive bottle feeding is important to make sure your baby is getting what they want to drink.

To make sure your baby can let you know when they have had enough, you can hold them in a slightly upright position. Encourage them to “latch” onto the bottle, like they would with the nipple and let them pause while they are drinking. Try and alternate which side you hold your baby, like they would be held when breastfeeding on different sides.

Source: responsive bottle feeding, UNICEF Baby Friendly Initiative 

Guide to bottle feeding Start4Life

How to combine breast and bottle (NHS)

Breastfeeding and baby weight

If you are breastfeeding, you might be tempted to add supplementary milk using a bottle, but this isn’t always the answer. Seek qualified breastfeeding support as soon as you can and, ideally, before you start to “top up” your baby’s feeds.

If you are struggling with any aspect of infant feeding, seek advice from a qualified infant feeding expert. Health Visitors are trained to support families to feed their babies, but sometimes more specialist support is required. When your baby is not gaining weight as expected, it can feel like you are failing, but this isn’t the case. You are doing all you can to support your baby, and you deserve good support. 

Sometimes, simple changes can make huge differences, and poor weight gain is not always a sign of something overly worrying. Seek support early and if you’re not sure about the advice you’re receiving, it’s fine to seek a second opinion. Some problems have to do with how your baby feeds (for example,tongue tie can affect up to 10% of newborns). Simple tweaks can make huge changes to how much milk a baby takes in.

Hannah Croft, IBCLC says, “Qualified infant feeding supporters will recommend keeping a close eye on your baby if weight gain is not as expected. However, the weight of a baby is just one indication of how things are going. We will usually also look at the baby holistically - how they behave, how alert they are, their nappy output and how they are feeding. It’s so important not to get fixated on weight, as anxiety and over-weighing can make things worse. The whole picture is important - how was the birth, were extra fluids given during labour to inflate that initial birth weight? A qualified breastfeeding expert will look at the entire picture and provide tailored support”.

Specialist breastfeeding support to encourage weight gain

Some Health Visitors are also Internationally Board Certified Lactation Consultants (IBCLCs). IBCLCs have the highest qualifications and experience in supporting breastfeeding. They are highly experienced professionals who will help you understand baby’s weight gain, support you in your breastfeeding goals and help with emotional support, too. They can often provide you with a plan if weight gain is not as expected and with tips and tricks specific to you and your baby.

Make sure to ask your midwifery team or Health Visitor what level of breastfeeding support training they have undertaken. If you need extra support, ask for a referral to an IBCLC. Depending on your area, you might be able to see an IBCLC on the NHS or via a charity or non-profit group. Many of these groups also have qualified breastfeeding counsellors, who also have a very high level of expertise in breastfeeding and troubleshooting problems. Peer supporters (those who have breastfed their own babies and received breastfeeding support training) can also help you with some issues, including getting good position and attachment.

Breastfeeding support

NHS breastfeeding support group finder 

Association of Breastfeeding Mothers 

La Leche League Support Group Locator

National Breastfeeding Helpline 0300 100 0212 from 9.30am-9.30pm every day of the year, including bank holidays 

Breastfeeding Network Peer Support Group Finder

National Childbirth Trust Breastfeeding Support  0300 330 0700

Association of Tongue Tie Practitioners

Expert in breastfeeding, Internationally Board Certified Lactation Consultant
Hannah Croft, IBCLC
Expert in breastfeeding, Internationally Board Certified Lactation Consultant
Hannah Croft, IIBCLC

Hannah Croft is an Internationally Board Certified Lactation Consultant. Hannah  achieved IBCLC status - the highest level of breastfeeding education - in 2018 after extensive study of 14 Science subjects, 90 hours of breastfeeding education and 1000 clinical hours. This built on her 4 years' experience as Breastfeeding Peer Supporter and Breastfeeding Counsellor. Hannah is based in Canterbury, Kent where she lives with her two children and husband. She is also a trained and qualified Norland Nanny and has many other qualifications and accreditations, including understanding of children's sleep, babywearing, baby massage, counselling and early childhood.

Cathy Tabner
Cathy Tabner

Cathy began her career as a staff nurse on a surgical ward before starting her midwifery training in 1985 in Stockport. Cathy has worked in a variety of clinical settings such as delivery suites, midwife led units and antenatal clinics, as well as providing postnatal care in hospital and community settings. My Expert Midwife supports parents-to-be from the minute they decide to try for a baby, through pre-conception and pregnancy supplements.  As well as award-winning natural skin products, they offer no-nonsense, evidence-based antenatal education led by registered midwives and are currently running a Baby Campaign to support and empower parents during the early stages. 

Parenting can be a minefield of information, if you need anything more to help navigate the first year, we have you covered with interview experts for breastfeeding positions, baby weaning and also sleep regression ages

Tannice Hemming
Maternity and family writer

Tannice Hemming has worked alongside her local NHS in Kent and Medway since she became a parent and is now a mum of three. As a Maternity Voices Partnership Chair, she bridged the gap between service users (birthing women and people, plus their families) and clinicians, to co-produce improvements in Maternity care. She has also worked as a breastfeeding peer supporter. After founding the Keep Kent Breastfeeding campaign, she regularly appears on KMTV, giving her views and advice on subjects as varied as vaccinations, infant feeding and current affairs affecting families. Two of her proudest achievements include Co-authoring Health Education England’s E-learning on Trauma Informed Care and the Kent and Medway Bump, Birth and Beyond maternity website.

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