Most 17-year-olds still have some growth left, though how much depends on sex, individual maturation, and where their growth plates stand. An MRI-based study of adolescents found that half of boys had not fully fused their growth plates until ages 15 to 18, with complete closure in all males not occurring until around 21. Girls tend to finish earlier, with complete fusion at all sites by around 19. So at 17, a boy could have centimeters still to gain, while a girl of the same age is more likely near her final height. The real question is not just your age on a calendar but how far along your skeleton has matured.
When Growth Plates Actually Close
Height increases because of cartilage structures near the ends of long bones called growth plates. These plates generate new bone tissue throughout childhood and adolescence, then gradually harden and fuse, locking in your final stature. The timing of this process is not the same everywhere in the body. In adolescents studied with MRI, the first growth plate to close was at the heel bone, followed by the lower leg, the knee, and finally the wrist. That sequence matters: even if an X-ray of your hand shows advanced bone maturity, the plates around the knee could still be open, meaning the legs can still contribute a bit of length.
The sex difference in timing is substantial. In the same study, the age at which 90% of girls had fused growth plates at all measured sites fell between 15 and 18. For boys, that window was 17 to 20.1PubMed Central. A cross-sectional magnetic resonance imaging study of factors influencing growth plate closure in adolescents and young adults A 17-year-old boy who entered puberty on the later side could easily have growth plates that are still open at the knee and wrist. A 17-year-old girl, by contrast, has a high probability of being done or very nearly done.
The Pubertal Growth Spurt and Its Timing
The biggest burst of height gain during adolescence is the pubertal growth spurt. On average, boys hit their peak growth rate at about 13.5 years, gaining roughly 9.5 cm in their fastest year. Girls peak earlier, around 11.5 years, with a slightly lower rate of about 8.3 cm per year.2PubMed. Growth and normal puberty After that peak, growth does not stop abruptly. It tapers off over several years. The total contribution of puberty to final height is about 30 to 31 cm in boys and 27 to 29 cm in girls, spread across the whole pubertal period.
Where you are in that trajectory at 17 depends on when your puberty started. A boy who began puberty at 11 may have already been through his peak growth rate years ago and could be finishing up. A boy who started puberty at 14 or 15 may still be in the thick of it at 17, with real gains ahead.
Constitutional Delay and “Late Bloomers”
Some teenagers simply develop on a later schedule. This pattern, called constitutional delay of growth and puberty, is a normal variation rather than a disorder. These teens enter puberty later, grow for longer, and usually reach a normal adult height, just on a delayed timeline.3PubMed Central. Boosting The Late Blooming Male: Use of growth promoting agents in the athlete with constitutional delay of growth and puberty If you are 17, shorter than your peers, and still showing signs of puberty progressing (voice deepening, facial hair filling in, continued growth over recent months), constitutional delay is a likely explanation. Boys with this pattern can keep growing into their early twenties.
The psychological toll can be real, even though the medical prognosis is fine. Being the shortest person in your friend group at 17 when everyone else has already shot up creates real anxiety. That is partly why some families seek medical evaluation even when the long-term outlook is reassuring.
Why Estrogen Determines the Finish Line
It might surprise you that the hormone most responsible for shutting down growth in both sexes is estrogen, not testosterone. Estrogen speeds up the aging of growth plate cartilage cells, pushing them toward the point where they can no longer divide. Once that proliferative capacity runs out, the growth plate fuses into solid bone.4PubMed Central. Effects of estrogen on growth plate senescence and epiphyseal fusion Boys produce estrogen too, just in smaller amounts, which is one reason their growth plates stay open longer.
Growth hormone and its downstream signal, IGF-1, are the main drivers of actual growth. During puberty, pulsatile growth hormone secretion roughly doubles compared with childhood, driven by larger bursts of the hormone rather than more frequent ones.5The Journal of Clinical Endocrinology & Metabolism. Gender and Sexual Maturation-Dependent Contrasts in the Neuroregulation of Growth Hormone Secretion in Prepubertal and Late Adolescent Males and Females So puberty creates a tug-of-war: growth hormone pushes bones to elongate while estrogen gradually erodes the cartilage that makes elongation possible. The outcome of that race determines your final height.6PubMed Central. Pubertal growth and epiphyseal fusion
Research in mice has shown that when the estrogen receptor responsible for growth plate closure is knocked out, bones keep growing substantially longer.7PubMed Central. The role of estrogen receptor-α and its activation function-1 for growth plate closure in female mice That finding underpins the logic behind certain medical therapies that try to delay estrogen’s effect, which we will get to shortly.
How Doctors Assess Your Remaining Growth
If you want more than a guess, doctors have a few tools. The most common is a bone age X-ray of the left hand and wrist. A radiologist compares the appearance of your bones and growth plates to a reference atlas to estimate how skeletally mature you are. Newer deep-learning models can now automate this assessment and also predict adult height from the same X-ray, with predictions falling within roughly 6 cm of the expert estimate for most patients.8PubMed Central. Automated Bone Age Assessment and Adult Height Prediction from Pediatric Hand Radiographs via a Cascaded Deep Learning Framework That sounds imprecise, but it is a useful ballpark, especially when combined with other information.
Another approach uses no X-ray at all: a model that predicts your percentage of adult height based on your current height, age, and sex. One such model is applicable up to age 17.5 and has been shown to be the most accurate height-percentage predictor that does not require bone age data.9Scientific Reports. Skeletal age prediction model from percentage of adult height in children and adolescents
Then there is the classic mid-parental height formula, which averages your parents’ heights (with an adjustment for sex) to give a “target height.” This explains a meaningful share of the variation in children’s heights, with parental stature accounting for a heritability estimate of about 74% in one recent analysis. However, children in that study were on average about 2.7 cm taller than their target height predicted.10PubMed Central. Accurate Prediction of Children’s Target Height from Their Mid-Parental Height The formula works best when both parents come from a similar population. A study in an Asian Indian population found that the standard formula underestimated actual heights, explaining less of the variance and requiring a population-specific correction.11PubMed Central. Tanner’s Target Height Formula Underestimates Final Height in Asian Indians – A Cross-sectional Observational Study So if you plug your parents’ heights into an online calculator and get a number, treat it as a rough guide, not a destiny.
Sleep, Nutrition, and Exercise
You have probably heard that sleep is critical for growth because growth hormone is released during deep sleep. That is true in the sense that a major pulse of growth hormone does coincide with the first bout of slow-wave sleep. But a study specifically designed to test whether sleep deprivation causes a 24-hour deficit in growth hormone found something unexpected: when the nighttime pulse was blunted by keeping subjects awake, the body compensated by releasing more growth hormone during the day, resulting in the same total amount over 24 hours.12PubMed. Effect of sleep deprivation on overall 24 h growth-hormone secretion The researchers concluded that occasional poor sleep is unlikely to stunt growth through a daily growth hormone shortfall. That said, chronic sleep disruption affects many other hormonal systems tied to growth and metabolism, so consistently short sleep is still not doing your body any favors.13PubMed Central. The impact of sleep and circadian disturbance on hormones and metabolism
Nutrition is a more powerful lever. Severe caloric restriction during adolescence can genuinely stunt linear growth. A study of adolescent boys with anorexia nervosa found that those who were gaining weight grew at a mean rate of about 7 cm per year, while those who continued to lose weight or failed to gain grew at only about 2.7 cm per year. Weight restoration triggered accelerated growth in all patients, sometimes up to 2 cm per month. Even so, most did not achieve complete catch-up to their expected height.14Pediatrics. Stunting of Growth as a Major Feature of Anorexia Nervosa in Male Adolescents The lesson here is that serious undernutrition can cost you height permanently, but you do not need a special “growth diet.” You need adequate calories and protein to support the growth you are already genetically programmed for.
As for exercise, a common worry is that weight training can damage growth plates and stunt height. The evidence does not support this. A review of experimental resistance training programs found that they did not influence growth in height or weight in adolescents.15PubMed. Weight training in youth-growth, maturation, and safety: an evidence-based review Lifting weights will not make you taller, but it will not make you shorter either.
Medical Options When Growth Is Running Out
For teens who are projected to end up significantly shorter than expected, there are medical interventions, though none are casual decisions. Growth hormone therapy can meaningfully boost growth velocity even in boys whose growth plates are nearing closure. In a pilot study of boys with predicted short adult stature and near-ending growth, growth hormone treatment for about 11 months resulted in a significant increase in final height compared to what had been predicted before treatment.16Growth Hormone & IGF Research. A pilot study of growth hormone administration in boys with predicted adult short stature and near-ending growth The FDA has approved growth hormone for use in growth-hormone-sufficient patients with idiopathic short stature, a category that can include some teens with constitutional delay.3PubMed Central. Boosting The Late Blooming Male: Use of growth promoting agents in the athlete with constitutional delay of growth and puberty
A more targeted approach uses aromatase inhibitors, drugs that block the conversion of testosterone to estrogen. By suppressing estrogen, they slow down growth plate fusion, buying more time for bones to elongate. In a randomized trial of boys with constitutional delay, those treated with the aromatase inhibitor letrozole alongside testosterone reached a mean near-final height of about 175.8 cm, compared with 169.1 cm in the placebo group.17PubMed. Treatment with the aromatase inhibitor letrozole during adolescence increases near-final height in boys with constitutional delay of puberty The letrozole group ended up matching their mid-parental target height, while the placebo group fell short of theirs. A separate trial confirmed the mechanism: letrozole slowed bone age advancement to just 0.9 years over an 18-month period, compared with 1.7 years in boys receiving testosterone with placebo.18The Lancet. Aromatase inhibition and bone maturation in boys with constitutional delay of puberty
A recent study combined letrozole with growth hormone in late-pubertal boys whose bone age was already advanced. Among those who reached their final height, the combination yielded a mean gain of about 6.6 cm over what had been predicted. The gains were largest in boys whose bone age was between 15 and 16, and still meaningful but smaller when bone age was between 17 and 18.19PubMed Central. Combined Letrozole and Growth Hormone Therapy in Late-Pubertal Males with Advanced Bone Age and Open Knee Physes The takeaway: the later you start, the less room there is to work with. These interventions are most effective when growth plates still have remaining capacity.
These treatments carry real trade-offs. Aromatase inhibitors affect estrogen throughout the body, not just at the growth plates, which raises concerns about bone density and other estrogen-dependent processes during a critical developmental window.20PubMed. Use of aromatase inhibitors to increase final height They are not supplements you can buy online and try casually. They are prescription medications used under endocrinologist supervision, typically reserved for boys with a clear clinical indication of short stature.
Why You Are Taller in the Morning
If you have ever measured yourself at different times of day and gotten different readings, you were not imagining things. Spinal discs lose fluid under the compressive load of standing and moving during the day, then reabsorb fluid overnight while you are lying down.21PubMed. Diurnal variations in intervertebral disc height affect spine flexibility, intradiscal pressure and contact compressive forces in the facet joints The net effect is a loss of roughly 7 mm in body height over the course of a day, according to MRI measurements.22PubMed. Diurnal variation in lumbar MRI. Correlation between signal intensity, disc height, and disc bulge That is not real growth, obviously, but it matters if you are tracking your height at home. Measure at the same time each day, ideally in the morning, if you want consistent numbers.
This daily fluctuation is also why posture improvements can create the appearance of gaining height. If you have been slouching through years of school and desk work, straightening up can reclaim one or two centimeters of height that was always there structurally but not being expressed. Again, this is not new bone growth. But if your concern at 17 is partly cosmetic, it is worth paying attention to.
Cosmetic Limb Lengthening Surgery
Once growth plates have fully fused, the only way to add real skeletal height is surgery. Limb lengthening uses a technique called distraction osteogenesis: a bone is surgically cut and then slowly pulled apart using an external or internal device, allowing new bone to form in the gap.23PubMed Central. Limb lengthening history, evolution, complications and current concepts Originally developed to correct deformities and limb-length discrepancies, this procedure is now offered cosmetically in some centers.
Cosmetic lengthening can add several centimeters to stature, but the process involves months of recovery, significant pain, and a meaningful complication rate that includes nerve damage, infection, and joint stiffness. It is expensive, typically costing tens of thousands of dollars, and not covered by insurance when done purely for height. For a 17-year-old whose growth plates are still open, this is not relevant yet and would be a strange choice. It is worth knowing about mainly so you understand that once the biological window closes, the remaining options are extreme.
Rare Genetic Factors That Affect Growth Trajectories
Most teens who worry about height fall within the range of normal variation. But some carry gene variants that cause stature to drift progressively shorter relative to peers. Mutations in the NPR2 gene, for instance, are found in a small percentage of people evaluated for short stature. In families with these mutations, carriers showed progressively lower height scores as they matured, whereas their unaffected siblings maintained steady height scores throughout childhood.24PubMed Central. Short Stature is Progressive in Patients with Heterozygous NPR2 Mutations The distinction matters clinically: if short stature is getting worse over time rather than staying proportionally stable, that pattern can prompt genetic testing and potentially change the treatment approach. For the vast majority of 17-year-olds wondering if they are going to keep growing, this is not the explanation. But if your growth has been slowing in a way that does not match the typical late-pubertal taper, it is worth raising with a doctor.