Baby Weight And Height Percentile Growth Chart

Remember that itchy belly skin (and possibly some resulting stretch marks) from pregnancy? Those were due to rapid stretching of your skin because babies grow so quickly. (1) Once your baby has been born, you can expect that rapid growth to continue. That tiny newborn that could almost fit in your hands could be knee-high or taller by their first birthday. An infant’s growth and development from newborn to toddlerhood is truly a marvel. Tracking this growth is important in knowing that they are growing as they should. Enter - the baby growth chart. 

What is the baby growth chart?

A baby growth chart is a trajectory chart for height, weight, and head circumference. Your baby’s stats will typically be tracked by age range on your pediatrician’s computer at each visit. This serves as a roadmap to your baby’s physical development. The data that your baby’s stats will be compared to is based upon collected data from a large population of babies of all ages in order to determine how your little one measures up against their peers. (2) From this information, your baby will be given percentiles based on where they fall for height or length, weight, and head circumference compared to other babies their age. For example, a baby whose weight falls in the 50th percentile weighs more than 50% of babies their age. Don’t be alarmed if your baby does not fall perfectly in the middle in each category as all babies are different sizes and grow at their own rate. What is most important is that your baby follows their own growth trajectory. 

How much should a baby weigh by age?

There are only general ranges for how much babies should weigh by age as sex, genetics, nutrition, and overall health can affect a baby’s weight. 

These averages are based upon data from The World Health Organization (WHO). (3)

Healthy babies can still fall outside the scope of these guidelines. The rate at which your baby gains weight will be a key factor when considering their health. Your child’s pediatrician is the best source for information if you are concerned about your baby’s weight. 

How do I calculate my baby's weight by age?

For infants under the age of 1, there is a formula that can be used to estimate their weight based upon averages for their age. (4) For this formula, kgs will be used instead of lbs. (1kg is approximately 2.2lbs). (5) To get an estimate of a baby’s weight based on their age, take their age in months and add 9, then divide by 2. Here is an example for a 5 month old: 5+9=14. 14/2=7. Therefore, an average weight for a 5 month old may be 7 kgs or 15.4 lbs.

This is just for estimation purposes. There are only a few instances where this formula would be needed and you should always rely on their true weight for medicine dosages and growth tracking purposes.

What is a normal percentile for baby growth?

There is no “normal” percentile for baby growth as each baby develops differently. Anything that falls between the 5th to 95th percentile can be considered normal. (6) Babies may still be healthy if they fall outside this scope and percentiles are truly just one piece of information when determining the health of a baby. What may be more concerning than a very high or very low percentile would be if a baby did not follow their own curve on their growth chart. 

Can baby weight indicate height?

Babies come in all shapes and sizes, a baby with a higher percentile for weight may not necessarily have a high percentile in length or height. Research does suggest though, that birth weight can be an indicator of a baby’s anticipated height as an adult. (7) 

Should baby height and weight percentiles match?

Height and weight percentiles do not have to match perfectly. It is expected that they be in roughly the same proportion though. (8) Your child’s pediatrician may want to evaluate reasoning for drastically different height and weight percentiles. For example, a baby who falls in the 80th percentile for height may need their nutritional intake monitored more closely if their weight falls in the 5th percentile. 

Should percentiles be concerning for babies?

Percentiles alone are not typically concerning for babies. Growth charts are simply one tool out of many that a pediatrician may use when assessing the health of a baby. Your baby may freely follow their own trajectory on the growth chart without any issues, regardless of their percentile. 

Do low percentile babies catch up?

Yes and no! It is very possible for a small baby to simply just be petite and may always follow a low percentage curve. Many babies with low percentiles do eventually catch up though. Roughly 85% of babies born small for their gestational age usually catch up to a “normal” range by the age of 2. (9)

Conclusion

As parents, there are seemingly a million things we worry about, including how our babies are growing. One thing you shouldn’t have to worry about is: sleep. Not only is sleep key to proper growth and development for your baby, it is also key for you to feel your best. If your baby isn’t sleeping, neither are you. For the best night’s sleep for you and your baby, you can count on Dreamland Baby’s sleep essentials. Our gently weighted Swaddles, Transition Swaddles, and Sleep Sacks are designed with CoverCalm® Technology to provide deep pressure stimulation that helps your baby fall asleep faster and stay asleep longer. 

Sources:

1. https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=aa88316&lang=en-ca 
2. Growth Charts - Background. 
3. https://www.healthline.com/health/parenting/average-baby-weight#weight-chart 
4. https://pubmed.ncbi.nlm.nih.gov/18021105/#:~:text=For%20Infants%20%3C%2012%20months%3A%20Weight,4%20x%20age%20in%20years. 
5. https://byjus.com/lbs-to-kg-converter-calculator/#:~:text=One%20pound%20is%20approximately%20equal,given%20pound%20value%20and%200.45359237.&text=Also%2C%20one%20kilogram%20is%20approximately%20equal%20to%202.2046226218%20lbs.
6. https://kidshealth.org/en/parents/growth-charts.html#:~:text=What's%20the%20Ideal%20Percentile%20for,is%20in%20the%2095th%20percentile. 
7. https://pubmed.ncbi.nlm.nih.gov/15703531/#:~:text=Background%3A%20Both%20birth%20length%20and,have%20not%20been%20fully%20evaluated.
8. https://www.eehealth.org/blog/2017/09/baby-growth-chart/#:~:text=Also%2C%20your%20child's%20height%20and,her%20nutritional%20intake%20more%20closely.
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4753194/#:~:text=Postnatal%20growth%20of%20SGA&text=The%20majority%20of%20infants%20born,17%2C18%2C19).