Growth Spurts in Teens: When They Happen and What to Expect

A growth spurt is a short period of unusually fast growth. The biggest one after babyhood comes with puberty: girls usually have theirs between about 10 and 14, with the fastest year around 11 to 12, and boys between about 12 and 15, with the fastest year around 13 to 14. In that peak year, teens typically grow 3 to 4 inches (8 to 10 cm).

Baby growth spurts vs. the teen growth spurt

If you searched this as a parent of a newborn: babies have several short growth spurts in their first year, often around 2 to 3 weeks, 6 weeks, 3 months, 6 months and 9 months. Each one usually lasts no more than a few days and brings extra hunger, fussiness and changes in sleep. A baby typically grows about 10 inches (25 cm) in the first year. The rest of this guide is about the much longer spurt of puberty.

Growth spurt ages for girls and boys

The averages come from a classic review of US growth studies. Normal is wider than the table: Cleveland Clinic gives roughly 9 to 15 for girls and 12 to 17 for boys. Starting early or late usually changes when you grow, not how tall you end up. To see what your current height and age suggest, try the height calculator.

When do boys hit their growth spurt?

Boys start puberty between about 9 and 14, usually with the testicles getting bigger, and their growth spurt arrives about two years later than girls'. Most boys grow fastest somewhere between 12 and 15.

When do boys have their biggest growth spurt?

On average, the single fastest year comes at about 13.5. But the spurt peaks in the later stages of puberty, not at the start. In a US study that followed children through puberty, most boys had not reached their peak until the fourth of the five puberty stages, when the genitals are close to adult size. The voice usually drops just after the peak.

So a boy with only a few early signs of puberty usually has his biggest growth still ahead. Late developers can peak at 15 or later, which is one reason late bloomers often catch up with their friends.

Growth spurt after pubic hair

Boys: Pubic hair appears early in puberty, soon after the testicles start growing. For most boys that means the fastest growth is still ahead. Underarm and facial hair usually show up about two years after pubic hair, often around or after the peak.

Girls: The spurt starts early. Pubic hair usually appears soon after breast buds (in about 15% of girls it comes first), and the fastest growth happens between breast budding and roughly six months before the first period. In the same US study, about 7 in 10 girls had passed their peak by the time their period started.

Signs of a growth spurt

• Fast height gain. Pants get short and shoes get tight within months.
• A bigger appetite. Hunger often jumps as your body needs more energy.
• Changes in sleep. Some teens feel more tired or want to sleep longer.
• Uneven growth. Hands, feet, arms and legs can grow faster than the rest of the body, which can make you feel out of proportion for a while.
• Other puberty changes. Body hair, breast development, a deepening voice or a first period often come with or around the spurt.
• Mood swings. Hormone changes and tiredness can make emotions feel bigger.

Cleveland Clinic notes that growth itself does not hurt. Active teens sometimes get pain and swelling below the kneecap during the spurt, called Osgood-Schlatter disease. It usually settles once bone growth stops.

How long does a growth spurt last?

The teen growth spurt is not a single burst. From the moment growth starts speeding up to the fastest year takes about two and a half years on average, and then growth tapers off over the next few years. Some teens notice it as a few separate bursts over a couple of years.

After the peak, growth winds down until it stops: usually around 14 to 15 for girls and 16 to 18 for boys. Our guides on when boys stop growing and when girls stop growing cover that stage.

How to force a growth spurt (and what actually helps)

You cannot force a growth spurt. It starts when your brain switches on puberty hormones, on a schedule strongly influenced by your genes, and genes explain about 80% of the differences in height between people. No food, stretch, exercise or supplement can trigger it early or make it bigger than your genes allow. Be wary of products that promise otherwise.

What you can do is give your body what it needs to reach its potential while the spurt is happening:

• Sleep 8 to 10 hours a night, the amount recommended for ages 13 to 18. Children and teens release growth hormone mainly during sleep. Read more in does sleep make you taller?
• Eat enough. Regular meals with protein, calcium-rich foods, fruit and vegetables cover what growing bones need. Dieting hard or training intensely without enough food can delay puberty.
• Stay active. Exercise and sports support healthy bones and muscles.
• Get regular checkups, so any health problem that slows growth is found early.

Never use growth hormone, testosterone or other hormones unless a pediatric endocrinologist prescribes them after testing. Our how to grow taller guide explains the evidence in more detail.

When to see a doctor

Talk to a doctor if:

• There are no signs of puberty by about 13 in girls or 14 in boys.
• Puberty starts before 8 in girls or 9 in boys.
• Your growth slows down sharply or stops for many months before puberty is finished.
• You are falling to lower percentile lines on your growth chart.
• Leg or knee pain is severe, makes you limp, causes swelling, or does not go away.

The short version

The teen growth spurt usually peaks around 11 to 12 for girls and 13 to 14 for boys, adding 3 to 4 inches in the fastest year. It comes early in puberty for girls and later for boys, so the timing of other signs tells you a lot about where you are. You cannot speed it up, but sleep, good food and activity help you get the most out of it.