What’s the most common question most pediatricians get?
No, it is not about eye color, although that’s a common one too.
It’s about how tall a child is going to get when they finish growing.
Can You Really Predict or Calculate Your Child’s Future Height?
Your pediatrician can’t see into the future, so how can they predict how tall your kids will be when they get older?
While it is true that we don’t have a crystal ball to help us see into the future, we do have a lot of science on our side that can help us get a glimpse.
So it’s not a trick, just basic genetics, which tells us that tall parents typically have tall children, and vice versa.
How To Predict Your Child’s Height
So how tall will your kids be?
How tall are you and your spouse or partner? In general, you can predict your child’s future height based on their genetic potential, which is based on their biological parents’ average height.
To see how tall your kids will be, you can:
- Record mom’s height (in inches).
- Record dad’s height (in inches).
- Average the two heights together.
- Do you have a girl? Subtract 2 1/2 inches from your average heights and that is your daughter’s predicted height as an adult.
- Do you have a boy? Add 2 1/2 inches from your average heights and that is your son’s predicted height as an adult.
While not perfect, your kids have a 68 percent chance of being within 2 inches and a 95 percent chance of being within 4 inches of this predicted height.
Want to test it out? See if you reached your own genetic potential by calculating what your own height should have been using your mom and dad’s height. Are you close?
But can’t you just double your child’s height when they are two year’s old? Doesn’t that predict their adult height too? While that is another method, it isn’t clear how accurate the prediction might be.
Another method might be to simply follow your child’s growth curve on a growth chart and see where they end up. Like the two years times two method, following the curve might not be accurate, as the growth curve incorporates an average age for starting puberty. Kids who start puberty on the later side of normal can benefit from a late growth spurt and continue growth in their late teen years that can push them up a few percentiles on the growth chart.
Being a late bloomer can be genetic though, so even if other methods underestimate your child’s height in this case, the genetic potential method might still be accurate.
Does any of this matter? It actually does and monitoring your child’s growth isn’t just something that parents do for fun.
If a child doesn’t seem to be reaching their genetic potential for growth, that could be a sign that something is getting in the way of their growing properly. Do they have uncontrolled asthma? Are they taking a medication that could affect their height, causing short stature? Do they have a thyroid, metabolic, or genetic condition?
Is your child already much taller than everyone in the family? While that is also sometimes a concern, as some conditions lead to excessive growth or a tall thin body type, the most common reason for a child to be taller than their parents is that their are other tall relatives in the family.
Talk to your pediatrician if you are concerned about your child’s growth or have questions about how tall or shot they might become.
What to Know About Predicting Your Child’s Height
While trying to predict your child’s future height is fun to do, it is also an important tool that your pediatrician might use to make sure they are growing properly and meeting their genetic potential for growth.
More on Predicting Your Child’s Height
- Predicting a Child’s Adult Height
- How to Read a Growth Chart: Percentiles Explained
- Growth Charts
- Growing awareness – your child’s height
- My child is short … is that OK?
- Being a late bloomer
- When a Child is Unusually Short
- When a Child is Abnormally Tall
- Delayed Puberty in Boys: Information for Parents
- What are the signs of Marfan syndrome?
Last Updated on May 13, 2018 by Vincent Iannelli, MD