Getting a baby is both exciting and stressful, especially for people who are new parents. Your baby’s birth weight is one of the first things you’ll be told. The question is, what is normal, and does it really matter?
Full-term baby girls weigh about 7 pounds 2 ounces (3.2 kg), and full-term baby boys weigh about 7 pounds 6 ounces (3.3 kg). Healthy babies can weigh anywhere from 5 pounds 8 ounces to 8 pounds 13 ounces. It’s normal for your child to lose a little money in the first week, so don’t worry about it.
Pay attention to steady growth instead of numbers. WHO standards are used by the CDC to keep track of growth during the first year. A good diet helps babies gain weight in a healthy way, whether they are fed formula or breast milk.
Main Points
- Most boys and girls who are fully grown weigh between 5 lb 8 oz and 8 lb 13 oz.
- A baby’s weight usually drops by 5 to 10 percent after birth.
- Patterns of growth are more important than a single number.
- WHO growth charts help keep track of progress.
- Long-term success is affected by how often you eat.
How to Figure Out the Average Newborn Weight
Birth weight is an important but variable statistic because every baby is different when they are born. Most full-term babies weigh between 5 lb 8 oz and 8 lb 13 oz, but kids born outside of this range are still healthy. This is what parents need to know.
How much do most babies weigh?
Clinicians look for babies that are under 5 lb 8 oz (low birth weight) or over 8 lb 13 oz (larger than normal) as outliers. These limits help find possible health problems. For instance, gestational diabetes can cause babies to be heavier at birth, while smoke can cause babies to be lighter.
Because they share a womb room, twins and triplets often weigh less. Because premature babies develop differently than full-term babies, they need different growth charts.
Low birth weight babies vs. bigger-than-average babies
Babies who were born less than 5 pounds 8 ounces may need more help with eating or keeping their temperature stable. Those who are over 8 pounds 13 ounces, on the other hand, might have trouble delivering. Neither one automatically points to long-term problems.
Keep in mind that the 50th percentile on growth charts is not the best; it’s just the middle place. Growth that stays steady over time is what matters most.
How a Baby’s Weight Changes in the First Few Weeks
During the first few weeks with your baby, many things will change, such as their body measures. It’s normal for babies to lose a little at first and then start to gain it back. Parents can surely see their child’s progress when they understand these patterns.
Why do babies lose weight at first?
A 5–10% drop is common in the first few days. Newborns lose extra fluids and go to the bathroom early. Babies who are fed formula often lose a little more than babies who are fed breast milk, but they catch up in two weeks.
Cluster feeding, or giving many small meals at once, helps the breast milk glands make milk and speeds up the healing process. This natural process makes sure that gains stay steady after the first drop.
When You Can Expect to Gain Weight
By 10–14 days, most babies are back to the size they were at birth. After that, you should aim for about 30 grams (1 ounce) of growth every day. Keep an eye out for these moments:
- Days 1 through 5: short-term loss of up to 10%.
- Week 2: The steady rise starts.
- After 14 days, consistent gains signal health.
If the loss is more than 10% or there is no regain after two weeks, you should see a doctor. These could mean problems with eating or other issues.
A timeline of a baby’s weight gain month by month
From the time they are born until their first birthday, kids grow in a known but unique way. Every kid grows and learns at their own pace, but keeping track of their progress every month helps make sure they’re doing well. This is what you can expect in the first year.
From birth to 3 months: Gaining weight quickly
The most growth happens in the first three months. Most babies gain one to two pounds every month, and by five months, they have often doubled their birth weight. There may be fussier feedings during growth spurts at 2–3 weeks and 6 weeks.
Formula-fed babies might gain a little more than 4–8 ounces per week, while breastfed babies usually gain the same amount. You can compare percentiles on WHO or CDC growth charts, not just for weight but also for length and head size.
Four to six months: steady growth
A lot of babies weigh 16 to 17.5 pounds by 6 months. The speed slows down a bit, but consistency is important. Around this time, you can start giving them food, but breast milk or formula should still be their main source of nutrition.
Preemies may “catch up” with their full-term peers and close the gaps in their growth. When keeping track of their growth, always use their corrected age.
7–12 Months: Gains are slower but steady.
The weight gain slows down to about 1 pound a month after 6 months. Most babies triple their birth weight by the time they turn one. Focus on eating foods that are high in nutrients to help with mobility tasks like crawling and walking.
Always keep in mind that percentiles are not grades. Any baby, whether they are in the 10th or 90th percentile, can be healthy if they follow their curve.
Things that affect a baby’s weight
Early growth trends are set by a mix of nature and care. Some things stay the same, but others can change to help good growth. What is your baby’s size?
Genes and Family History
60 to 80% of birth weight is determined by genes. If parents were small or big as babies, their child might be the same. Race and the health of the mother during pregnancy are also important.
Method of Feeding: Formula-fed vs. breastfed
Formula-fed babies gain about 6.7 ounces per week, while breastfed babies gain about 5.9 ounces. Both ways provide all the food needed, but the rates of growth are slightly different. Cluster feeding helps babies who were breastfed catch up.
Health Problems and Being Born Early
Some health problems, like heart issues that are present at birth, can slow growth by 20 to 30 percent. If a mother has diabetes, her baby can be 15% bigger at birth. Before their due date, preemies use maps that have been changed.
- Feeding choices and growth are affected by cultural customs.
- People with celiac disease or allergies may need to change what they eat.
- Often, kids who were born early “catch up” on their growth later.
How to Use Charts for Baby’s Growth
Growth charts are very important for keeping track of an infant’s growth. Standardized benchmarks help parents and doctors keep track of a child’s growth. Learning how to read these charts can help you relax and celebrate big steps.
How to Understand Percentiles
Percentiles show how a baby stacks up against other babies the same age. 50% of babies in that group weigh more than or equal to that amount. The range from 5th to 95th is normal.
A baby in the 90th percentile isn’t “overweight”; they’re just bigger than 90% of babies their age. It’s not just about having a single high or low number.
WHO vs. CDC Growth Standards
The Centers for Disease Control and Prevention (CDC) charts show information from babies who were fed formula or breast milk. Based on 8,000 breastfed babies, the World Health Organization (WHO) guidelines show how babies should grow.
People with kids younger than 2 years old should use WHO charts because
- Focus on nursing as the normal thing to do for babies.
- Focus on ideal growth instead of averages.
- Don’t worry too much about how quickly formula-fed babies gain weight.
Take the case of a 6-month-old who is in the 75th percentile on WHO charts but would rank lower on CDC charts. Follow their trends over time, not just a few numbers.
You can download the WHO Growth Charts and the CDC Growth Charts.
Keep an eye on your baby’s weight at home.
You can make sure your baby is growing well by keeping track of their growth at home. You can feel better between doctor visits with simple notes and tools. Pay attention to patterns, not just numbers.
How to Tell If You’re Gaining Weight Healthily
Keep an eye out for these good signs:
- 6–8 diapers a day: This shows that the baby is getting enough water and food.
- Alertness between feeds: A happy, awake baby is a good sign.
- Aim for 4–8 ounces of steady weight gain every week after the first two weeks.
Milestones in development, like being able to hold their head up, are just as important as learning to count. Enjoy the little wins!
When to Talk to a Pediatrician
Get in touch if you see:
- Gains less than 4 ounces a week.
- A soft spot or a fontanelle that has sunk in.
- Not more than six wet diapers in 24 hours.
Texas Children’s Pediatrics suggests seeing a lactation expert if breastfeeding makes it hard to gain weight in a healthy way. Trust your gut; you know your child best.
Do-It-Yourself Tracking Tip: Weigh yourself every week on a precise scale. Make notes on the results to give to your doctor at checkups.
How to Eat to Gain Weight in a Healthy Way
Nutrition is very important for your baby’s early growth, and picking the right way to feed them sets the stage. Technique and regularity are the most important things, whether you breastfeed, use formula, or do both.
How to Make Breastfeeding Work
During the first 24 hours, babies need 8 to 12 feeds, usually in short, regular sessions. A good latch makes sure that the milk moves quickly; shoot for 15 to 20 minutes on each side. During growth spurts, it’s normal to feed in clusters (back-to-back sessions).
Keep an eye out for signs of hunger, such as digging or sucking. If latching hurts, you should talk to a lactation expert. Texas Children’s Baby Bistro is one resource that can help with problems.
Instructions for Formula Feeding
Prepare 2.5 ounces per pound of body weight every day for babies who are fed formula. To keep water from getting dirty, use water that is at room temperature and clean the bottles. Holding the bottle horizontally while you eat helps you avoid eating too much.
- Mixing: Carefully follow the directions on the package.
- Switching: Do it slowly so you don’t upset your stomach.
- Solids: Purees should be introduced between 4 and 6 months, but formula or breast milk should still be the main source of nutrition.
Common Worries About How Much a Baby Weighs
Parents often worry about whether their child is growing too quickly or too slowly. Even though most changes are normal, knowing what causes them and how to fix them can help ease your worry.
Why people gain weight slowly and how to fix it
About 4% of babies gain weight slowly, which is usually because they are having trouble eating or are sick. Less wet diapers or feeling tired are signs. Failure to thrive is defined by the American Academy of Pediatrics as being below the third percentile.
Some solutions are:
- Lactation experts can help with latch problems or not having enough milk.
- Formulas high in calories: choices with 22 to 24 calories per ounce help babies who are underweight catch up.
- Metabolic testing: people with rare diseases like celiac disease may need to follow special meals.
Are you having trouble with rapid weight gain?
Rapid weight gain may make you 30% more likely to become obese. Common reasons are overfeeding or overflow syndrome (too much breast milk). Watch for signs that they are full, like turning away, during bottle feeds.
A infant nutritionist can change meal plans if problems keep happening. To check for good growth, look at weight-for-length ratios instead of just scale numbers.
In conclusion
Healthy growth isn’t about reaching a certain point; it’s about making steady progress. Most full-term babies weigh between 5 lb 8 oz and 8 lb 13 oz when they are born, but their growth curve is more important than a single number.
Along with scale numbers, keep track of events like being awake and diaper counts. Pediatric checkups are important to make sure your child does well during their first year and beyond.
As a toddler grows, new trends appear, but the idea behind it stays the same: consistency is better than comparison. Trust your baby’s unique path of growth; they are writing their own story.
Q&A
What is the average weight at birth?
Most babies born at full term weigh between 5.5 and 8.8 pounds when they are born. The Centers for Disease Control and Prevention (CDC) says that there are small differences based on genetics and the health of the mother.
Why do some kids lose weight after they are born?
Little ones often lose up to 10% of their body mass in the first week because they lose water. If they get the right food, they generally get it back in two weeks.
How fast should my kid grow in the first year?
You can expect quick gains of 5 to 7 ounces every week until month 3. After that, it will go up more slowly but steadily. Many triple their birth weight by their first birthday.
Does a baby who is breastfed or given formula grow in different ways?
Yes. According to the World Health Organization, kids who are breastfed gain weight faster at first but may weigh a little less by month 6. Both designs are good for you.
When should I be worried about moving slowly?
Talk to your doctor if your baby doesn’t gain the weight they lost after birth by 14 days, falls below the growth chart percentiles, or has fewer wet diapers than expected.
Are the CDC and WHO’s growth charts not the same?
Of course. WHO standards show the best growth for babies who are nursed, while CDC charts show growth for babies fed in different ways. Pediatricians often use both together.
Can I keep track of growth at home without a scale?
Yes! Stay aware and keep an eye on diaper changes (6 or more wet diapers per day) and regular clothes size changes. Clinical scales are more accurate than home scales.
What ways of eating help with healthy gains?
For nursing moms, make sure the baby is properly latched and fed 8 to 12 times a day. Babies who are fed formula usually drink 2 to 3 ounces every three hours. Look out for signs of hunger, like digging.
Does fast growth ever worry you?
If you’re making too many gains, you might want to talk to your doctor, especially if you’re crossing multiple percentile lines quickly.