What is a Growth Chart and How to Read It

Shortly after your baby is born, they will have their first appointment with their new pediatrician. The doctor will examine your baby, check their reflexes, measure his or her head circumference, and measure your baby’s height and weight. The doctor will also review your baby’s growth chart with you at that point.

What Are Baby Weight Charts?

A baby weight chart, also known as a baby growth chart, contains a series of percentile curves that closely track how your baby grows and develops compared with other children of the same age. These growth standards are based on head circumference, weight-for-length, weight-for-age, and length-for-age.

On average, boys tend to be heavier and taller than girls, so there are separate charts for each gender.

Baby Weight Percentile Explained

The percentile curves on the baby growth chart reflect how your baby compares to other babies her age. So, if your newborn daughter is at the 50th percentile for weight-for-age, that means that 50 other baby girls weigh less than her, while 50 weigh more. And, all of that just means that your little one is of average weight! (Though, of course, we know you know how exceptional she is!)

Three to four days after coming home from the hospital, you’ll likely bring your little one into the pediatrician’s office for their first well-baby check where the doctor will repeat the measurements taken in the hospital. Don’t be alarmed if he or she weighs a little less than when they were born. Babies can lose around 10% of their weight shortly after birth. This is quite normal, and your pediatrician will let you know if there is otherwise any reason for concern.

Baby Girl Growth Chart

According to the World Health Organization (WHO), the average weight for a full-term baby girl at birth is 7 pounds, 2 ounces, or 3.2 kilograms. A full-term newborn girl’s average height is 19.29 inches or 49 centimeters.

Baby Boy Growth Chart

The WHO also states that the average weight for full-term baby boys at birth is 7 pounds, 6 ounces, while the average height is 19.69 inches or 50 centimeters. 

Reading the Infant Growth Chart

When you look at your child’s chart as they get older, it’s important to focus on how they’re growing, not the numbers. Remember, the number is a set data point, not a school grade. Over time, your child may have periods of little change or experience growth spurts. What’s most important is that they’re thriving and progressing.

What Baby Weight Percentile is Normal?

A baby growth chart is simply a tool to help your doctor track your child’s growth. It’s not meant to make you feel bad or worry extra about your baby. Baby’s weight and height charts measure your little one’s overall health, nutrition, and growth over time. Don’t forget, “normal” can look different for every baby!

What Happens if My Baby is Above or Below the Average?

If your baby's growth continues to follow a percentile line on the charts closely, they are considered to be growing at an average rate even if they are below the 5th percentile or above the 95th.

Factors That Affect Weight

Many factors affect weight for every human being. These include such things as genetics, family history, environment, activity, and nutrition.

Breastfeeding

Of course, breast milk contains important fats, proteins, vitamins, and minerals that contribute to your baby’s nutrition, health, and growth. It also protects against disease, helps establish a healthy digestive system, and can even impact a child’s development. 

A healthy breastfed infant may put on weight more slowly than a formula-fed baby in the first year of life. If that’s the case for your baby, remember that steady weight gain and growth are what’s important. Clearly, the benefits of breastfeeding far outweigh any concern for slightly slower-paced weight gain. But if on the rare occasion or special situation that your pediatrician recommends supplementation, remember that’s okay!  It just means that your nutritious breast milk combined with formula will be exactly what your precious little one needs to thrive and grow. 

Formula Feeding

Formula-fed babies typically gain weight more quickly after about three months of age. Experts are unsure of why this is the case. What’s most important to keep in mind is that studies show by the time they are age two, breastfed and formula-fed babies weigh about the same.

Watching your little one grow and develop as the weeks, months, and years pass is exciting. Baby growth charts help you and your pediatrician make sure your precious new baby is on the right track to a long, healthy life.