What Is Obese for a 13 Year Old? The Real Numbers Explained

Understanding Obesity in Teens: It’s More Than Just a Number

When it comes to figuring out if a 13-year-old is obese, you can't just look at a weight chart and call it a day. Nope. It’s all about BMI-for-age percentiles, which sounds super technical (and kinda is), but bear with me.

At this age, kids are growing at wildly different rates — some hit puberty early, others not at all yet. So it’s not just how much they weigh, but how that weight compares to their height, age, and gender. Context matters. A lot.

What BMI Is Considered Obese for a 13-Year-Old?

The standard used in the U.S. (and in many other countries) comes from the CDC growth charts. Here’s the deal:

• Underweight: Less than the 5th percentile

• Healthy weight: 5th to less than the 85th percentile

• Overweight: 85th to less than the 95th percentile

• Obese: 95th percentile or higher

Okay, but what does that mean in plain English?

Let’s say a 13-year-old boy is 5 feet 1 inch (about 155 cm) tall:

• A healthy weight might range from 90 to 115 pounds (41–52 kg)

• A weight over 130 pounds (59 kg) could put him in the obese range, depending on exact height and build

For girls, it's similar — just slightly different due to body composition changes during puberty.

But again: don’t just look at pounds or kilos. Always calculate BMI-for-age using a tool like the CDC’s child BMI calculator.

Why BMI Percentile and Not Just BMI?

Because teens’ bodies change fast. A BMI of 22 for a 13-year-old might be totally fine for one kid and high for another. The percentile tells you how that BMI compares to peers of the same age and sex.

Let’s be honest: some 13-year-olds are still kid-shaped, others look nearly adult. So comparing them without adjusting for age and sex? Kind of pointless.

Signs That Go Beyond the Scale

Numbers help, but they don’t tell the whole story.

Physical signs

• Clothes feeling tight even after normal growth

• Difficulty running, climbing stairs, or staying active

• Stretch marks or dark patches on skin (especially around the neck or underarms) — could indicate insulin resistance

Emotional and social signs

• Avoiding sports or gym class

• Feeling self-conscious at school

• Bullying, teasing, or low self-esteem

And hey — none of this is about shame. It's about spotting signals early, so kids can grow into healthy adults without added stress.

What Causes Obesity at 13?

Ah, the million-dollar question. It's rarely just one thing.

Lifestyle and habits

• Too much screen time, not enough movement (TikTok isn’t cardio)

• Sugary drinks, frequent fast food, oversized portions

• Skipping breakfast and eating late at night

Genetics and hormones

Some kids are simply predisposed — their bodies store fat differently. Add in puberty hormones, and things can get unpredictable fast.

Emotional factors

Stress, boredom, anxiety — all of these can lead to overeating or emotional eating. Especially if food = comfort.

What to Do If You’re Worried

First off: Don’t panic, don’t shame, don’t scold. That never helps.

Start with a pediatrician

Get a proper BMI assessment. Talk about habits. Rule out medical causes like thyroid issues or PCOS (in girls).

Focus on the whole family

Healthy changes stick better when everyone’s on board. Swap soda for water. Make dinners at home. Go for family walks — whatever feels doable.

Oh, and let the teen have a say. No one likes being micromanaged, especially at 13.

Final Thoughts: It’s a Journey, Not a Quick Fix

So—what is obese for a 13-year-old? Technically, it's a BMI at or above the 95th percentile. But behind that stat is a real kid with real feelings, hormones, and a growing body still figuring itself out.

The goal isn’t to label or shame — it’s to support, guide, and encourage. With the right help, knowledge, and mindset, any teen can find their way to health without losing confidence in the process.

And let’s be honest: we could all use a little less judgment and a little more kindness. Especially at 13.

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.