What Makes a Person Very Tall? Genetics, Hormones, and Surprises

Genetics: The #1 Height Predictor

Blame (or thank) your parents

Let’s not dance around it — height is mostly inherited. If both your parents are tall, chances are you’re gonna tower over people too.
According to multiple studies, up to 80% of your final height is determined by genetics.
But hey, it’s not an exact formula. There are short parents with tall kids (and vice versa). Genes like to mix things up.

There’s a rule-of-thumb formula that tries to predict it:

(Father’s height + Mother’s height ± 13 cm) ÷ 2
Still not perfect — but close enough.

It’s not just one “tall gene”

There are actually hundreds of genes involved in height. Some regulate growth hormones, others affect cartilage and bone length.
The variety is wild — which is why even siblings can end up totally different in height. My brother’s 6'3", I’m 5'10". Same parents. Life’s not fair.

Growth Hormones: The Body’s Elevator Button

Human Growth Hormone (HGH)

The pituitary gland in your brain pumps out HGH, which stimulates bone and tissue growth — especially during puberty.
Too little of it = short stature (a condition called growth hormone deficiency).
Too much = gigantism (if it happens in childhood) or acromegaly (in adults).

You’ve probably heard of athletes or bodybuilders using synthetic HGH. But unless it’s prescribed for medical reasons, that’s a risky road.

Puberty timing matters

The age you hit puberty can affect your height too.
Early puberty = bones stop growing sooner.
Late puberty = more time to stretch out.
And yeah, that’s why some kids shoot up like trees at 16 while others barely hit their growth spurt before 18.

Nutrition and Lifestyle: The Growth Boosters (or Blockers)

Eat right, grow right

Even with tall genes, malnutrition can stunt height.
Key nutrients?

• Protein: for bone and muscle

• Calcium and Vitamin D: for bone density

• Zinc and iron: for overall growth processes

Kids who eat junk 24/7 and never see sunlight? Not ideal.
On the flip side, a healthy diet, sleep (growth hormone spikes during sleep!), and regular activity all support natural growth.

Bad habits that may hold you back

• Smoking (even second-hand)

• Heavy stress at a young age

• Sleep deprivation
  All of these can interfere with your growth window — especially during those crucial teenage years.

Rare Conditions That Cause Extreme Height

Gigantism and Marfan Syndrome

Some people grow abnormally tall due to rare medical conditions.

• Gigantism: Too much growth hormone from the pituitary gland, usually due to a tumor

• Marfan syndrome: A genetic disorder that causes long limbs and flexible joints. Not all Marfan patients are tall, but it’s a common feature.

There’s also something called Sotos syndrome and other overgrowth syndromes. These aren’t common, but they’re worth mentioning.

Not all tall people have disorders

Just because someone’s 7 feet tall doesn’t mean they’re sick. Some are just genetically blessed (or cursed, depending on airplane seat size).

Cultural and Environmental Differences

Some populations are taller — and it’s not just genes

People from the Netherlands, for example, are among the tallest in the world.
Average Dutch male height? Around 6 feet (183 cm).
Why? Strong genetics, but also great health care, diet, and living conditions.

In contrast, in regions where food insecurity or childhood illness is common, average heights are often lower — even with good genetic potential.

Final Thoughts: So, What Really Makes Someone Tall?

It’s a combo platter:

• Mostly genetics

• A big dash of hormones

• Plenty of nutrition

• And a bit of luck (plus maybe avoiding injuries that mess with growth plates)

There’s no one-size-fits-all answer. But one thing’s clear: being tall isn’t just about DNA — it’s how all the pieces come together during your body’s key growing years.

So next time you look up (literally) at someone 6’7”?
Remember — their story is more than just genes. It’s biology, timing, and a touch of mystery.

Is 165 cm normal for a 15 year old?

The predicted height for a female, based on your parents heights, is 155 to 165cm. Most 15 year old girls are nearly done growing. I was too. It's a very normal height for a girl.

Is 160 cm too tall for a 12 year old?

How Tall Should a 12 Year Old Be? We can only speak to national average heights here in North America, whereby, a 12 year old girl would be between 137 cm to 162 cm tall (4-1/2 to 5-1/3 feet). A 12 year old boy should be between 137 cm to 160 cm tall (4-1/2 to 5-1/4 feet).

How tall is a average 15 year old?

Average Height to Weight for Teenage Boys - 13 to 20 Years

How to get taller at 18?

Staying physically active is even more essential from childhood to grow and improve overall health. But taking it up even in adulthood can help you add a few inches to your height. Strength-building exercises, yoga, jumping rope, and biking all can help to increase your flexibility and grow a few inches taller.

Is 5.7 a good height for a 15 year old boy?

Generally speaking, the average height for 15 year olds girls is 62.9 inches (or 159.7 cm). On the other hand, teen boys at the age of 15 have a much higher average height, which is 67.0 inches (or 170.1 cm).

Can you grow between 16 and 18?

Most girls stop growing taller by age 14 or 15. However, after their early teenage growth spurt, boys continue gaining height at a gradual pace until around 18. Note that some kids will stop growing earlier and others may keep growing a year or two more.

Can you grow 1 cm after 17?

Even with a healthy diet, most people's height won't increase after age 18 to 20. The graph below shows the rate of growth from birth to age 20. As you can see, the growth lines fall to zero between ages 18 and 20 ( 7 , 8 ). The reason why your height stops increasing is your bones, specifically your growth plates.