Eighteen is the age when a lot of people check the doorframe one more time and wonder if there's any growing left. If you're searching for how to grow taller at 18, the honest answer is that most of your height is already in place. Genes set most of the range, and for most people the growth plates in the long bones have closed or are about to. Late bloomers can still add a little, and the habits you keep now protect your bones for decades. This guide covers how tall 18-year-olds typically are, how much growth is realistically left, how to tell if you're still growing, and what to skip.
Key Takeaways
- The median 18-year-old is about 5'9.4" (176.2 cm) for boys and 5'4.2" (163.1 cm) for girls on the CDC growth charts.
- Most girls finish growing by about 15 and most boys by about 17, so growth after 18 is usually small.
- Late bloomers, especially boys who started puberty around 14, may still grow a little at 18.
- Teens through age 18 need 8 to 10 hours of sleep and 1,300 mg of calcium a day; these habits matter most while growth plates are open.
- Stretching, hanging, and height pills can't lengthen bones once growth plates close, and hormones should never be used for height without a medical diagnosis.
Can You Still Grow Taller at 18?
For most people, only a little, and for many, not at all. Bones grow longer at the growth plates near their ends, and those plates usually close near the end of puberty, around ages 13 to 15 for girls and 15 to 17 for boys [1]. Once they close, bone length is set.
Timing varies, though. Boys usually start puberty between 9 and 14 and take about 3.5 to 4 years to complete it [2]. A boy who started at 14 may still be finishing puberty, and gaining a bit of height, at 17 or 18. Girls generally start and finish earlier, so growth at 18 is uncommon for them. The only way to know for sure whether growth plates are still open is a bone age X-ray, which a doctor can order if there's a reason to check.
How Tall Is the Average 18-Year-Old?
On the CDC growth charts that U.S. doctors use, the median height at 18 is about 5'9.4" (176.2 cm) for boys and 5'4.2" (163.1 cm) for girls [3]. The healthy range is wide:
| Percentile | Boys | Girls |
|---|---|---|
| 5th | 5'4.7" (164.2 cm) | 5'0.0" (152.5 cm) |
| 25th | 5'7.5" (171.3 cm) | 5'2.5" (158.8 cm) |
| 50th (median) | 5'9.4" (176.2 cm) | 5'4.2" (163.1 cm) |
| 75th | 5'11.3" (181.0 cm) | 5'5.9" (167.5 cm) |
| 95th | 6'1.9" (187.8 cm) | 5'8.4" (173.8 cm) |
An 18-year-old at the 5th percentile and one at the 95th differ by about 8 to 9 inches, and both can be perfectly healthy. Where you land mostly reflects your parents' heights. To see how your current height compares with the range your family's heights point to, try our Height Predictor Calculator.
How Much Growth Is Left After 18?
The growth charts show just how much height growth slows by the late teens. The chart below tracks how much the median height rises from one birthday to the next.
How much the median height rises each year, ages 12 to 19
Inches gained from one birthday to the next, based on the CDC growth chart median. Hover over or tap a column to see centimeters.
Inches per year
Takeaway: by 18, the median boy adds less than a quarter inch in the next year, and the median girl almost nothing. Source: CDC growth charts.
For boys, the median climbs about 3 inches a year at the peak of puberty, then drops to about a third of an inch between 17 and 18 and less than a quarter inch between 18 and 19. For girls, it's under a tenth of an inch at both ages. Keep in mind that these are changes in the median on the chart, not a promise for any one person. A late-maturing boy can still be gaining more, while an early maturer may have stopped years ago.
Signs You May Still Be Growing
A few clues suggest there's some growth left:
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Your height is still changing. Measurements taken the same way a few months apart keep going up.
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Puberty started late and is still progressing. For boys, that can mean the voice is still deepening or facial and body hair is still filling in.
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You grew noticeably in the past year. A recent growth spurt usually tapers off rather than stopping overnight.
To track it accurately, measure barefoot against a wall at the same time of day each time, ideally in the morning. Our guide on when boys stop growing explains the timing in more detail.
What Determines Your Final Height?
Genetics is the biggest factor: scientists estimate that about 80% of the differences in height between people come from inherited DNA [4]. The rest reflects how well your body was supported while it was growing, including nutrition, sleep, overall health, and chronic illness during childhood and the teen years. By 18, most of that story has already been written, which is why the habits below are about finishing well and protecting your bones rather than adding inches.
How to Grow Taller at 18: Habits That Still Matter
1. Sleep 8 to 10 Hours
The American Academy of Sleep Medicine recommends 8 to 10 hours a night for teens ages 13 to 18 [5]. Even if your growth plates have closed, good sleep supports recovery, mood, and focus.
If they're still open, sleep matters for another reason. In young adults, the biggest burst of growth hormone usually comes shortly after falling asleep, during the first period of deep sleep [6], so cutting sleep short works against whatever growth is left.
2. Stay Active, Including Strength Work
At 18, U.S. guidelines shift to the adult targets: 150 to 300 minutes of moderate activity a week, plus muscle-strengthening activity on at least 2 days [7]. Exercise doesn't stretch bones longer, but weight-bearing and strength training build bone density, and the late teens and twenties are when you're building the bone you'll carry into later life.
3. Eat Enough Protein and Calcium
Calcium needs stay high through 18, at 1,300 mg a day, then drop to 1,000 mg for adults 19 and older [8]. Milk, yogurt, cheese, fortified plant milks, and canned fish with bones are easy sources. Pair that with protein at every meal and enough vitamin D, and avoid crash diets, which shortchange the nutrients your bones need. If you're unsure whether your weight fits your height, our BMI Calculator includes a Kids & Teens tab that compares your BMI with others your age and sex, the CDC method used through age 19.
4. Keep Up With Checkups
Regular checkups let a doctor compare your height with earlier measurements and spot anything unusual, such as growth that stopped very early or puberty that never fully progressed.
Make the Most of the Height You Have
Posture can't lengthen bones, but slouching hides height. Weak core muscles encourage slumping, and tight chest muscles pull the shoulders forward; building core strength and flexibility can improve posture within a few weeks [9]. You're also a little taller in the morning than at night, because the discs in your spine compress during the day. In one study, that daily swing averaged about 14 mm, a little over half an inch [10]. That's why morning measurements read slightly taller, and why "gains" from hanging or stretching disappear by evening.
What Won't Make You Taller
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Stretching, hanging, and inversion tables. They can feel good and ease stiffness, but any extra height is temporary.
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Height pills and "growth" programs. No supplement can lengthen bones after growth plates close. Be wary of any product that promises a specific number of inches.
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Hormones and steroids. Growth hormone is a prescription treatment for specific medical conditions, such as a diagnosed growth hormone deficiency. It's not a height booster for healthy teens or adults, and using hormones or anabolic steroids without a doctor's supervision can cause serious harm.
What about vitamins? The American Academy of Pediatrics says healthy children who eat a normal, balanced diet don't need supplements beyond the recommended amounts, and megadoses can be harmful [11]. The same logic applies to healthy teens. Doctor Taller supplements are designed for children and teens who are still growing, to help fill nutrient gaps alongside a balanced diet; once growth plates have closed, no supplement can add height.
When to See a Doctor
Talk to a doctor if:
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You haven't started puberty, or it began and then stalled. Boys who show no signs of puberty by 14 should be checked [2], and the same applies to girls with no breast development by about 13.
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You're still growing quickly well after 18, or you notice changes in your hands, feet, or facial features.
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You've lost height, have back pain with a change in posture, or have a curve in your spine.
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Worry about height is affecting your mood, eating, or daily life.
A doctor can review your growth history, order a bone age X-ray if needed, and refer you to a specialist when something needs a closer look.
Final Thoughts
So, how do you grow taller at 18? For most people, the bigger growth years are already behind them, and any remaining change will be small. If you're a late bloomer, you may still add a little, and good sleep, enough food, and regular activity give your body the best chance to finish strong. Either way, those same habits build the bone strength you'll rely on for the rest of your life. Stand tall, skip anything that promises inches, and talk to a doctor if something about your growth doesn't seem right.
References
1. Nemours KidsHealth. Growth plates. kidshealth.org
2. MedlinePlus. Delayed puberty in boys. medlineplus.gov
3. Centers for Disease Control and Prevention. CDC growth charts data files: stature-for-age, 2 to 20 years. cdc.gov
4. MedlinePlus Genetics. Is height determined by genetics? medlineplus.gov
5. Paruthi S, et al. (2016). Recommended amount of sleep for pediatric populations. J Clin Sleep Med. doi.org
6. Van Cauter E, et al. (1998). Interrelations between sleep and the somatotropic axis. Sleep. doi.org
7. U.S. Department of Health and Human Services (2018). Physical Activity Guidelines for Americans, 2nd ed. health.gov
8. MedlinePlus. Calcium in diet. medlineplus.gov
9. Harvard Health Publishing. Why good posture matters. health.harvard.edu
10. Leatt P, et al. (1986). Spinal loading during circuit weight-training and running. Br J Sports Med. bjsm.bmj.com
11. American Academy of Pediatrics. Where we stand: Vitamin supplements for children. healthychildren.org
