Growing taller
How to Grow Taller at 18
By the Taller team · Updated · 5 min read · How we write
At 18, most people are close to their adult height. The average 18-year-old boy grows only about 0.2 in (0.4 cm) more in the next year, and most girls have already finished. You can’t lengthen your bones once your growth plates close, but if they are still open, sleep, nutrition and staying active help you reach your full genetic height, and good posture makes sure you stand at it.
Bottom line: at 18, focus on finding out whether you are still growing and on standing tall.
How much can you still grow at 18?
These are the CDC medians, the middle of the range for US kids. Your own numbers depend on your genes and on when your puberty started.
| Boys | Girls | |
|---|---|---|
| Median height at 18 | 5'9.5" (176 cm) | 5'4" (163 cm) |
| Median growth in the next 12 months | 0.2 in (0.4 cm) | 0.1 in (0.1 cm) |
| Median growth left before adulthood | 0.3 in (0.7 cm) | 0.1 in (0.2 cm) |
| Share of adult height already reached | 100% | 100% |
| Median adult height (age 20) | 5'9.5" | 5'4.5" |
Where most 18-year-olds are in puberty
Boys: At 18, most boys have finished or nearly finished growing. A small amount of growth until about 21 is possible for late bloomers whose growth plates are still open.
Girls: At 18, girls have almost always reached their adult height.
Puberty timing explains most of the height differences between friends of the same age. If you want to see where you are, read growth spurts in teens and signs of a late bloomer.
What actually helps you grow at 18
- Sleep 8 to 10 hours a night. That is what the CDC recommends at your age, and growth hormone is released mostly during deep sleep. See does sleep make you taller?
- Eat enough, with protein at every meal. Growing bodies need energy. Undereating or strict dieting during puberty can hold growth back.
- Get calcium and vitamin D. Teens aged 9 to 18 need 1,300 mg of calcium and 600 IU (15 mcg) of vitamin D a day (NIH). Milk, yogurt, cheese, fortified plant milks, tofu and fish help. See foods that help you grow.
- Move at least 60 minutes a day. The CDC’s guideline for kids and teens includes bone-strengthening activity like running and jumping three days a week. Supervised strength training is fine (it doesn’t stunt growth).
- Avoid what slows growth: nicotine and vaping, alcohol, and chronic lack of sleep. See what stunts growth.
- Stand tall. Posture doesn’t lengthen bones, but slouching can hide height. A few daily stretches help.
What won’t make you taller
No pill, gummy, “HGH booster”, stretching routine or hanging bar can make your bones longer than your genes allow. Growth hormone is a prescription treatment for specific medical conditions, and testosterone or steroids taken without a doctor can close growth plates early and leave you shorter. See does HGH make you taller? and vitamins for height.
Signs you’re still growing at 18
- You grew noticeably in the last 6 to 12 months (measure yourself against the same wall every few months).
- Your shoe size is still going up, or your pants are suddenly too short.
- Your puberty changes are still progressing (for boys: voice still changing, facial hair still filling in).
Our “Am I done growing?” quiz puts these signs together. Only a bone-age X-ray can confirm whether your growth plates are still open.
When to see a doctor
- You haven’t grown at all in a year and you think you should still be growing.
- You are much shorter than your parents’ heights would suggest, or you have dropped across percentile lines on your growth chart.
- There are no signs of puberty by about 14 (boys) or 13 (girls).
- Your growth worries you. A pediatrician can check your growth curve and, if needed, refer you to a pediatric endocrinologist.
Frequently asked questions
How tall should a 18-year-old be?
On the CDC growth charts, the median height at 18 is 5'9.5" (176 cm) for boys and 5'4" (163 cm) for girls. A wide range around these numbers is normal, because puberty starts at different ages.
How much will I grow after 18?
An average 18-year-old boy still grows about 0.3 in (1 cm) before adulthood; an average girl about 0.1 in (0 cm). Early bloomers usually have less left and late bloomers more. Our height calculator gives a personal estimate.
Is it too late to grow taller at 18?
Not always. Boys who are late bloomers can still grow a little until about 18 to 21 if their growth plates are open. Once the plates have closed, no exercise, food or supplement can add height.
Can stretching or hanging make me taller at 18?
Stretching and hanging don’t make bones longer. They can loosen tight muscles and improve posture, so you stand at your full height, but the effect on measured height is small and temporary.
Sources
- Clinical Growth Charts (2000 CDC stature-for-age) — CDC / National Center for Health Statistics
- About Sleep: How much sleep do I need? — CDC
- Physical Activity Guidelines for Children and Adolescents — CDC
- Calcium — Fact Sheet for Consumers — NIH Office of Dietary Supplements
- Vitamin D — Fact Sheet for Consumers — NIH Office of Dietary Supplements
- Puberty — Nemours KidsHealth
Other ages
Keep reading
This page is for general education and is not medical advice. Growth is very individual: if you are worried about your height, growth or puberty, talk to a doctor or a pediatric endocrinologist.