How Tall Will My Child Be?

Published on June 29th, 2020 and Updated on April 29th, 2021


It’s mind-boggling how fast your baby grows. With each doctor’s appointment, you get the latest update on height, weight, and percentiles, and it’s always shocking. Even without these numbers, you can see the change—the first onesie grows tighter, tighter, and then a larger size is needed. In every picture, your child looks a little different; your friends and relatives can’t stop saying, “she’s getting so big!”

Soon she’ll be tall enough for the “You Must be This Height” rides at the amusement park. 

It’s hard not to wonder: How tall will my child be?

Stages of Growth

It may feel like your baby’s growth accelerates every month—but he actually had the biggest growth spurt of his life in your belly. In nine months, your baby went from a height of 0 inches to his birth height, which is generally around 18 to 22 inches. That rate of height growth is generally never experienced again.

All people go through the following stages:

  • Fetal growth – During this stage, insulin plays a central role in growth.
  • Childhood growth – Children grow at a rate of about two inches a year up until they are eight years old. In childhood, boys and girls grow at similar rates. During this stage, nutrition plays a central role in the amount and speed of growth.
  • Puberty – Children undergo a growth spurt, with boys growing more rapidly than girls. Regulating factors of puberty include:
    • Growth hormone (secreted from the pituitary gland)
    • The sex hormones estrogen and testosterone (which aid bone formation and activate growth hormone)
  • Adult height and growth plate fusion – A great percentile of girls reach their adult height at 15, while most boys reach their full height at 17 or 18. While some growth may occur over the next few years, the majority of a person’s height growth is finished by these age ranges.

Until your child has reached the adult phase, his height is not set in stone but determined by a variety of factors.

Factors that Affect Height

How tall will your child be? Some online child height projection tools take just two factors into account to predict your child’s height: the mother’s height and the father’s height. But if you have siblings, you know it’s more complicated than that: two sisters can have very different heights. 

Human height depends on many factors, including:

  • Genetics
  • Nutrition
  • Exposure to disease 

Genetics vs Nutrition vs Disease: Which factor matters most?

Determining a child’s eventual adult height can be summarized as follows: 

  • Genetics set the boundary for how tall a child can be. 
  • Proper nutrition helps the child realize their potential height.
  • Disease and environmental factors can hinder their growth pattern.

Therefore, as long as the child grows up healthy (with regards to diet and disease), their adult height can be determined through genetics.

Role of Genetics in Height Prediction

Molecular biologist Chao-Qiang Lai explains in Scientific American that in European populations, height seems to be about 80% hereditary. In contrast, in Asian countries, a child’s future height may be only 65% hereditary—meaning that diet, disease exposure, and other factors can play a greater role in a child’s growth pattern and eventual adult height for different populations. 

This difference in heritability is due to generational environmental effects. “When a given environment maximizes the genetic potential of a population for a given trait, this population tends to have a higher heritability for that trait, and vice versa.” So, countries that have offered strong nutritional environments for generations have increased the heritability of height. However, despite the differences between populations, genetics are still the largest factor of adult height in all people.

These genes aren’t all summed up in “tall” or “short” genes. Similar to traits like hair color and eye color, your child’s future height is polygenic—that is, a number of different genes play a role in determining height. In fact, there are as many as 3,290 gene variants that affect height. 

Researchers in Nature found that, of 21 studied chromosomal loci, 13 contained “a known skeletal growth gene.” The most well-studied genes involved in height regulate the activity at cartridge growth plates. These areas at the end of bones grow new bone, effectively adding length to a leg or arm bone (and thus increasing height). 

Examples of important genes that influence height include:

  • GDF5 – The “growth differentiation factor 5” gene helps regulate the  child’s normal growth of cells and tissues, including bone and cartilage
  • IHH – This gene encodes a protein involved in bone growth
  • While many genes are involved in determining height, none has a huge effect on its own. 

While many genes are involved in determining height, none has a huge effect on its own. Researchers Brian McAvoy and Peter Visscher found that “The DNA variant with the largest effect on height only has an impact of about five millimetres, and most of the other variants have a much smaller effect.” 

5 mm or 0.19 inches hardly affects whether your child is tall enough to be the first pick at volleyball. Instead, height is the result of the complex interactions of the many genes that regulate the proteins and hormones involved in child growth. 


Did your mother ever tell you that you had to drink milk to grow up tall and strong? While milk is not the only possible source of the nutrients, she may have been onto something. At a population-wide level, better nutrition is associated with increased future height.
Nutrition is also a key factor in helping your kid maintain a healthy weight and lifestyle.

When it comes to nutrition for growth, all the basics you’ve been taught about diet apply. To reach their full potential height, your child needs:

  • Fresh fruits and vegetables
  • Adequate protein
  • Calcium
  • Other vitamins that support bone growth, including vitamins D and K
  • Iron

Exposure to Disease; Access to Medication

Researchers Carlos Bozzoli, Angus Deaton, and Climent Quintata-Domeque share that wealthier, healthier populations are statistically taller. By plotting infant mortality vs. adult height, they find that nations where children are exposed to more health risks have shorter populations. Based on this research,

“The early-life burden of undernutrition and disease not only is responsible for mortality in childhood but also leaves a residue of long-term health risks for survivors, risks that express themselves in adult height and in late-life disease.”

Giving additional credence to these findings, researchers Albertine Berard and Martin Blaser found that children who face less exposure to microbes during their developmental period grow up to be taller adults. These researchers suggest that the availability of antibiotics that kill off microbes help children to reach their maximum potential adult height.

While some medications (i.e., antibiotics) may aid in children’s growth, childhood exposure to other medications may impede it. There is a body of research suggesting certain ADHD medications are tied to shorter stature, for example.

A General Prediction of Child’s Height

If you are really curious to get an estimated height prediction of your child with some simple math, follow these steps from the mid-parental height calculator method:

  • Step 1: Add both parent’s heights together in inches or centimeters.
  • Step 2: On top of the total combined parental height, add an extra 5 inches or 13 centimeters if it’s a boy and subtract if it’s a girl. If you’re pregnant and don’t know your child’s gender yet, see if you’re eligible to take our Gender Prediction Test with our eligibility calculator
  • Step 3: Divide the net total by 2 to get the predicted height of your child.

This calculation will give you a rough estimate of your child’s average height when they are fully grown. Although there is no confidence that this is accurate, you can assume that your child’s height will be around one standard deviation away from the predicted average (which is 5 inches taller or shorter than the calculated estimate).

How to Get an Accurate Child Height Projection

As a parent, you’re dedicated to nourishing your baby with a full range of nutrients, as well as keeping them safe from disease. So you know you’ll have some influence on your child’s height through your nurturing. But what about when it comes to nature? You might want to know if your baby boy will turn into an extra-tall adult or stay short and sweet.

The most accurate way to get a picture of your baby’s eventual elevation is to look at the genes that influence height. For that, you need a DNA test.

Does your mind ever wonder “What color hair will my baby have?” Are you looking for a safe, private way to gain more insight into your child’s adult height, as well as other genetic traits, like nutritional profile? Luckily, SneakPeek will be introducing the SneakPeek Early Traits DNA Test in Fall 2020. 

Complete your at-home DNA test in just three steps:

  • Take a quick rub of your child’s inner cheek with a cotton swab. 
  • Send the cotton swab back in a prepaid envelope 
  • In 2-3 weeks, receive your child’s genetic profile.

When the results arrive, you’ll gain insight into so much, including your child’s adult hair color, eye color, and yes, how tall they’ll be. With this test, develop an even deeper understanding of the beautiful being you’ve brought into the world.

Taking the DNA sample is pain-free, and your child’s data is privacy-protected.

The SneakPeek Early Traits DNA Test

Questions like “When does baby hair texture change?” or “Will my baby’s eyes stay blue?” are actually very normal questions to have about a baby. As a parent, it’s natural to want to know everything you can about your growing child. You’ll love them whether their hair changes texture or their eyes change color. But the more you know about your baby, the better you can care for them and prepare your family for the future. That’s why we’re creating the SneakPeek Early Traits DNA Test. With these results, you’ll better understand your child’s growth and development needs, including their genetic predispositions for sleep behavior and nutritional needs. 

For a sneak peek into your baby’s future, let’s take a look together this fall.


  3. Perspectives in Biology and Medicine. The ecology of height.
  4. Nature. Hundreds of variants clustered in genomic loci and biological pathways affect human height.
  5. Economics & Human Biology. Genetics of human height.
  6. Gene cards. GDF5 gene.
  7. National Institute of Health. Is height determined by genetics?
  8. Scientific American. How much of human height is genetic and how much is due to nutrition?
  9. Demography. Adult height and childhood disease.
  10. Medpage Today. ADHD tied to shorter stature in early childhood.
  11. WebMD. Round out your child’s plate.
  12. American Journal of Medical Genetics. Endocrine control of growth.
  13. Healthline. When Do Boys Stop Growing?
  14. Healthline. Height in Girls: When Do They Stop Growing, What’s the Median Height, and More.

Subscribe for Updates

Related Posts

June 2, 2021
Your new baby is a bundle of joy. A miraculous source of wonder. A piece of your heart, experiencing the outside world for the first...
May 26, 2021
The house is quiet, the lights are dim, and your baby is finally asleep. As you watch your sleeping cutie doze peacefully in his...
May 21, 2021
Sleep, eat, nap, eat, sleep again—your newborn baby’s sleep cycle schedule is the stuff of vacation dreams. Unfortunately,...

Follow Us

Subscribe for Updates

SneakPeek aims to provide the most accurate and up-to-date information to help our readers make informed decisions regarding their health before, during, and after pregnancy. This article was written based upon trusted scientific research studies and/or articles. Credible information sources for this article are cited and hyperlinked.

What is the difference between Refer a Friend and Affiliate Program?
What do I do if the blood sample does not coat the test tube and mix with the preservative?
How do I dispose of the SneakPeek Snap device?
What is the maximum amount of time I should leave SneakPeek Snap on my arm if I’m not collecting enough blood?
Can my SneakPeek Snap helper be male?
What do I do if no blood at all is collected with SneakPeek Snap?
How does the microneedle part of SneakPeek Snap work?
Can I use SneakPeek Snap on my leg instead?
Will tattoos affect my blood sample and results with SneakPeek Snap?
I didn’t get enough blood the first time, can I try it again with the same SneakPeek Snap device?
Can I have a helper for using SneakPeek Snap?
How can I request that the raw data from my SneakPeek Traits DNA sample is deleted?
Can I request the raw data from my SneakPeek Traits DNA sample?
How does the test work and is it accurate?
What is the SneakPeek Traits testing process?
How are the SneakPeek Traits reports developed?
How will I be notified when my SneakPeek Traits reports are ready?
How can I view my SneakPeek Traits reports?
When will my SneakPeek Traits sample be received at your lab? How will I know it arrived safely?
How long does the SneakPeek Traits Results process take?
When will I receive my SneakPeek Traits collection kit?
My child did not cooperate with swabbing, and I was not able to fully collect both swabs.
The swab accidentally touched my child’s teeth, lips, or gums.
I dropped a swab on the floor before swabbing the child, or something else happened to the swab. Can I wash the swab?
I accidentally touched the swab head with my fingers.
There are two swabs in my At-Home DNA Swab Kit. Can I use them on two different people?
Can SneakPeek Traits Early DNA Test be used during pregnancy?
Does SneakPeek Traits Early DNA Test enable me to find DNA relatives or matches?
Is SneakPeek Traits Early DNA Test a paternity test?
Who can use SneakPeek Traits Early DNA Test?
If I purchase a second test for a different family member at a separate time, how are the tests linked together under the same main family account?
Can I purchase additional reports for a family member?
Why is SneakPeek Gender more accurate now?
Why do I need to wait until 8 weeks, when there are 7-week women in the study?
What if I can’t hear my baby’s heartbeat?
Is it safe to use a Fetal Doppler?
How does a Fetal Doppler work?
I used last menstrual period (LMP) to calculate 8 weeks into pregnancy. Are my test results reliable?
Can I purchase SneakPeek early and take it when I’m at 8 weeks?
If I can’t enter a post office due to social distancing or limited hours, are there other ways to return?
Is COVID-19 impacting SneakPeek shipping or results timelines?
In light of COVID-19, is SneakPeek Labs still accepting return samples?
Are SneakPeek products safe from COVID-19?
Why has the results email changed to show a check mark instead of a percentage?
How do I activate my SneakPeek At-Home test kit?
Can I buy the SneakPeek test kit now and use it later?
Influencer Collaboration
Is SneakPeek a pregnancy test?
My blood sample was taken at a participating location. What is the status of my results?
Is shipping free?
Does taking progesterone or other hormones affect my results?
Do blood thinners affect my results?
Do you ship to APO/FPO/DPO addresses?
I’ve seen gender predictor tests that use urine samples. How is SneakPeek different?
What is the difference between SneakPeek Gender At-Home and SneakPeek Gender Clinical?
Can I take the SneakPeek Test if I’m breastfeeding?
Do hormone disorders such as PCOS affect my results?
How is my privacy protected?
Is the test safe?
How quickly will I receive my refund?
When is SneakPeek Customer Care available?
What do I do if I have a question about my order?
I’m having twins. Can SneakPeek determine the gender of each one?
What is SneakPeek’s guarantee?
I’ve previously had a boy. Will that affect my test result?
Does a previous miscarriage affect my test results?
How do I ensure an accurate test result?
I can’t find my results email, what do I do?
When will I receive my results?
How are my results given to me?
How will I know you received my sample?
I don’t want my gender results to be sent to my email address. Can I have them sent to someone else?
What email address should I provide during checkout?
Can I track my sample?
What is the shipping timeline?
How long does my sample stay stable after collection? How long can it stay stable during shipping?
What is the difference between SneakPeek Standard and SneakPeek FastTrack?
Can I use SneakPeek if I am having a multiple-birth pregnancy?
How is the DNA blood sample taken?
How accurate is the SneakPeek Early Gender DNA Test?
When can I use the SneakPeek test?
When in my pregnancy can I take the SneakPeek Test?
Do you have a pregnancy calculator that tells me when I can take the test?
How does the SneakPeek Test work?