Average Height and Weight for Children by Age (6–12 Years)
The school years are when parents start comparing. Class photos line kids up by height, the nurse's office sends home a weigh-in, and it's hard not to wonder how your child measures up. The good news is that ages 6 to 12 are the calmest, most predictable stretch of growth in childhood. Here's the average height and weight at every age from 6 to 12, the normal range around those averages, how much kids typically grow and gain each year, how doctors decide whether a child's weight is healthy, and the signs that are actually worth raising with your pediatrician.
- Quick Answer
- Average Height and Weight by Age (6–12 Years)
- Normal Height Range by Age
- Normal Weight Range by Age
- How Much Kids Grow and Gain Each Year
- Why Girls Pull Ahead Around Age 11
- Is My Child's Weight Healthy? Why Doctors Use BMI
- Is My Child Short or Tall for Their Age?
- How to Measure Height and Weight at Home
- How to Support Healthy Growth From 6 to 12
- When to Talk to a Doctor
- FAQs
Quick Answer
At age 6, the average child is about 3'9" (115 cm) tall and weighs about 45 lb (20.5 kg). By age 12, the average boy is about 4'11" (149 cm) and 90 lb (40.7 kg), and the average girl is about 4'11½" (151.5 cm) and 92 lb (41.8 kg). These are the 50th percentile (median) values on the CDC growth charts used by U.S. pediatricians.[1] Between 6 and 12, most children grow a steady 2 to 2½ inches a year, while yearly weight gain roughly doubles, from about 5 lb at age 6 to about 10 lb by age 11.[1] A child well above or below these averages can be completely healthy. Doctors judge weight by BMI-for-age, not weight alone, and what matters most is steady growth along a child's own curve.[2][10]
Average Height and Weight by Age (6–12 Years)
The table below shows the median height and weight for boys and girls at each birthday from 6 to 12. Half of children that age are above these numbers and half are below. For the years before this, see our guide to average height and weight for babies and toddlers (0–5 years).
| Age | Boys — Height | Boys — Weight | Girls — Height | Girls — Weight |
|---|---|---|---|---|
| 6 years | 3'9.5" (115.7 cm) | 45.8 lb (20.8 kg) | 3'9.3" (115.0 cm) | 44.8 lb (20.3 kg) |
| 7 years | 4'0" (122.0 cm) | 51.1 lb (23.2 kg) | 3'11.9" (121.8 cm) | 50.4 lb (22.9 kg) |
| 8 years | 4'2.4" (128.1 cm) | 56.8 lb (25.8 kg) | 4'2.3" (127.8 cm) | 56.8 lb (25.8 kg) |
| 9 years | 4'4.7" (133.7 cm) | 63.2 lb (28.7 kg) | 4'4.4" (133.1 cm) | 64.2 lb (29.1 kg) |
| 10 years | 4'6.7" (138.8 cm) | 70.7 lb (32.1 kg) | 4'6.4" (138.2 cm) | 72.9 lb (33.1 kg) |
| 11 years | 4'8.6" (143.7 cm) | 79.5 lb (36.1 kg) | 4'8.8" (144.3 cm) | 82.4 lb (37.4 kg) |
| 12 years | 4'10.8" (149.3 cm) | 89.7 lb (40.7 kg) | 4'11.6" (151.5 cm) | 92.2 lb (41.8 kg) |
Source: CDC stature-for-age and weight-for-age growth chart data (50th percentile), values for children who have just reached each birthday, rounded to one decimal place.[1]
Two things stand out. From 6 to 10, boys and girls are almost exactly the same height, with the gap never more than about a third of an inch. Then around 9 to 11, girls start to edge ahead, first in weight and then in height, and by 12 the average girl is nearly an inch taller and about 2½ pounds heavier. To see exactly where your own child lands, our Height and Weight Calculator by Age and Growth Percentile Calculator use the same CDC reference data.
Normal Height Range by Age
An average is just the middle of a wide spread. The CDC charts show that healthy children of the same age and sex can easily differ in height by 6 inches or more. The table below shows the band between the 5th and 95th percentiles, where 90% of children fall.
| Age | Boys (5th–95th percentile) | Girls (5th–95th percentile) |
|---|---|---|
| 6 years | 42.2–48.8 in (107–124 cm) | 42.1–48.8 in (107–124 cm) |
| 7 years | 44.6–51.6 in (113–131 cm) | 44.5–51.7 in (113–131 cm) |
| 8 years | 46.8–54.3 in (119–138 cm) | 46.7–54.3 in (119–138 cm) |
| 9 years | 48.7–56.7 in (124–144 cm) | 48.5–56.6 in (123–144 cm) |
| 10 years | 50.5–59.0 in (128–150 cm) | 50.2–58.9 in (127–150 cm) |
| 11 years | 52.1–61.2 in (132–156 cm) | 52.1–61.6 in (132–156 cm) |
| 12 years | 54.1–63.7 in (137–162 cm) | 54.8–64.4 in (139–163 cm) |
Calculated from the CDC's published LMS parameters for stature-for-age at each birthday.[1]
Normal Weight Range by Age
Weight varies even more than height. At age 12, the 95th percentile is roughly twice the 5th percentile, because weight reflects both how tall a child is and how their body is built. That's why a weight number on its own says little about whether a child is healthy.
| Age | Boys (5th–95th percentile) | Girls (5th–95th percentile) |
|---|---|---|
| 6 years | 37.3–59.6 lb (16.9–27.0 kg) | 36.2–60.4 lb (16.4–27.4 kg) |
| 7 years | 41.3–68.1 lb (18.7–30.9 kg) | 40.2–69.4 lb (18.2–31.5 kg) |
| 8 years | 45.6–77.8 lb (20.7–35.3 kg) | 44.4–79.9 lb (20.1–36.2 kg) |
| 9 years | 50.1–89.0 lb (22.7–40.4 kg) | 49.2–92.2 lb (22.3–41.8 kg) |
| 10 years | 55.0–101.8 lb (24.9–46.2 kg) | 54.8–106.2 lb (24.9–48.2 kg) |
| 11 years | 60.6–115.9 lb (27.5–52.6 kg) | 61.4–121.2 lb (27.8–55.0 kg) |
| 12 years | 67.4–130.7 lb (30.6–59.3 kg) | 68.7–135.9 lb (31.2–61.6 kg) |
Calculated from the CDC's published LMS parameters for weight-for-age at each birthday.[1] These ranges describe how U.S. children are distributed, not a "healthy weight" range. See the BMI section below.
How to read a percentile: a 9-year-old at the 25th percentile for height is taller than 25% of 9-year-olds of the same sex and shorter than 75%. It's a position in a line-up, not a grade. A child who has tracked along the 10th percentile since kindergarten is growing just as well as one who tracks along the 90th.
▶ Watch: Growth Chart Basics in 3 Minutes
Watch on YouTube ↗How Much Kids Grow and Gain Each Year
After the rapid growth of the toddler years, height settles into a steady pace. A review in American Family Physician describes normal growth for children between age 5 and puberty as about 5 cm (2 inches) a year.[2] Weight follows a different pattern: on the CDC median curves, the amount gained each year climbs steadily through these years.[1]
| Age span | Boys — Height | Boys — Weight | Girls — Height | Girls — Weight |
|---|---|---|---|---|
| 6 → 7 | +2.5 in (6.4 cm) | +5.3 lb (2.4 kg) | +2.7 in (6.8 cm) | +5.6 lb (2.5 kg) |
| 7 → 8 | +2.4 in (6.1 cm) | +5.7 lb (2.6 kg) | +2.4 in (6.1 cm) | +6.4 lb (2.9 kg) |
| 8 → 9 | +2.2 in (5.6 cm) | +6.5 lb (2.9 kg) | +2.1 in (5.3 cm) | +7.5 lb (3.4 kg) |
| 9 → 10 | +2.0 in (5.1 cm) | +7.5 lb (3.4 kg) | +2.0 in (5.1 cm) | +8.6 lb (3.9 kg) |
| 10 → 11 | +1.9 in (4.9 cm) | +8.8 lb (4.0 kg) | +2.4 in (6.0 cm) | +9.5 lb (4.3 kg) |
| 11 → 12 | +2.2 in (5.6 cm) | +10.1 lb (4.6 kg) | +2.8 in (7.2 cm) | +9.8 lb (4.4 kg) |
Differences between consecutive CDC 50th percentile values.[1] Individual children grow in uneven spurts, so a single year can look faster or slower than this.
Put together, the median child gains about 13 to 14 inches and 44 to 47 pounds between 6 and 12.[1] Notice the dip in height gain for boys around 9 to 11. Growth tends to slow slightly just before puberty, then picks up again once the growth spurt begins. Because girls start that spurt earlier, their height gains climb from age 10 while boys are still in the slower phase. You can work out your own child's yearly growth rate from two measurements with our Height Velocity Calculator.
Why Girls Pull Ahead Around Age 11
The crossover around 11 is about timing, not final size. Puberty typically begins between ages 8 and 13 in girls and between 9 and 14 in boys,[5] and girls usually have their growth spurt between 10 and 14, while boys' spurt comes about two years later on average.[6]
Is My Child's Weight Healthy? Why Doctors Use BMI
Weight-for-age is useful for tracking growth over time, but the CDC does not use it to classify children as underweight or overweight. A tall 9-year-old will naturally weigh more than a short one. Instead, doctors use BMI-for-age, which adjusts weight for height and then compares the result with children of the same age and sex.[10]
| BMI-for-age percentile | CDC weight category |
|---|---|
| Below the 5th percentile | Underweight |
| 5th to less than the 85th percentile | Healthy weight |
| 85th to less than the 95th percentile | Overweight |
| 95th percentile or higher | Obesity |
CDC BMI categories for children and teens ages 2 through 19.[11]
BMI-for-age is a screening measure that opens a conversation about growth, not a diagnosis.[12] A child in the overweight or underweight range needs a fuller look from a pediatrician, who will consider growth history, family patterns, and how the child eats, sleeps, and moves. You can check your child's number with our Child & Teen BMI Percentile Calculator. Whatever the result, focus on family habits rather than the number on the scale, and talk to your pediatrician before changing a child's diet to target a specific weight.
Is My Child Short or Tall for Their Age?
Doctors define short stature as height more than 2 standard deviations below the average for age and sex, and tall stature as more than 2 standard deviations above it,[3] which corresponds to roughly the bottom and top 2 to 3 percent of children. Even then, most short or tall children simply have normal variants of growth, such as short or tall parents or a later or earlier puberty.[2] Only about 5% of children referred for short stature turn out to have an identifiable medical cause.[2]
The most useful comparison is with the family, not the class. Pediatricians estimate a child's genetic target with the mid-parental height formula: for boys, add 13 cm (5 inches) to the mother's height and average it with the father's; for girls, subtract 13 cm from the father's height and average it with the mother's.[4] You can run the numbers in seconds with our Mid-Parental Height Calculator, and read more about the role of genetics in determining height.
How to Measure Height and Weight at Home
A comparison with the chart is only as good as the measurement. A few small habits make home readings far more reliable:
- Shoes off, hair down: remove shoes and flatten ponytails or buns that push the head forward.
- Back to a flat wall: heels, buttocks, shoulders, and the back of the head lightly touching the wall, feet together, eyes looking straight ahead.
- Use a flat object for the top: a hardcover book held at a right angle to the wall gives a cleaner mark than a hand.
- Weigh on a hard floor: use the same scale on a flat, hard surface, in light clothing, at the same time of day.
- Track months, not days: record the date with every reading and compare changes over several months, not from one week to the next.
For the full step-by-step method, see how to measure height correctly, and check a reading with our Height Measurement Accuracy Checker.
How to Support Healthy Growth From 6 to 12
Genetics sets the range for a child's height, but everyday habits help them grow to their full potential within it and keep weight gain on a healthy track.
- Enough calcium: the recommended intake is 1,000 mg a day for ages 4 to 8 and 1,300 mg a day for ages 9 to 13.[7] Check your child's needs with the Calcium Intake Calculator for Kids & Teens.
- Balanced meals: enough protein, energy, and micronutrients overall matters as much as any single nutrient. See the nutrition and height connection.
- 9 to 12 hours of sleep: that's the recommended amount for children aged 6 to 12.[8] Learn how sleep affects height growth.
- 60 minutes of activity a day: children aged 6 to 17 should be active for at least an hour daily, including bone-strengthening activities like running and jumping on at least 3 days a week.[9]
- Know the age-specific steps: our guides on how to grow taller at 10 and how to grow taller at 12 put these habits into a daily routine.
When to Talk to a Doctor
A pediatrician can review the growth curve, check puberty stage, and, if needed, order a bone age X-ray to see how much growth is left. Our Height-for-Age Z-Score Calculator is an educational tool, not a replacement for that evaluation. For common causes of slow growth, see factors that stunt growth in children.
FAQs
What is the average height and weight for an 8-year-old?
How much should my child grow and gain each year between 6 and 12?
How do I know if my child's weight is healthy?
Is it normal for girls to be taller than boys at 11 or 12?
My child is the smallest in the class. Should I worry?
Can I predict my child's adult height?
References
- [1] Centers for Disease Control and Prevention, National Center for Health Statistics. CDC Growth Charts Data Files: stature-for-age and weight-for-age, 2 to 20 years (LMS parameters and selected percentiles). cdc.gov/growthcharts/cdc-data-files.htm
- [2] Barstow C, Rerucha C. Evaluation of short and tall stature in children. American Family Physician. 2015;92(1):43-50. aafp.org
- [3] Caro R, Savel P, Moss PI. Evaluation of short and tall stature in children. American Family Physician. 2025;111(6):532-542. pubmed.ncbi.nlm.nih.gov/40531152
- [4] Nwosu BU, Lee MM. Evaluation of short and tall stature in children. American Family Physician. 2008;78(5):597-604. aafp.org
- [5] Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Puberty and precocious puberty. nichd.nih.gov
- [6] Nemours KidsHealth. Growth and your 13- to 18-year-old. kidshealth.org
- [7] NIH Office of Dietary Supplements. Calcium: fact sheet for health professionals. ods.od.nih.gov
- [8] Paruthi S, et al. Recommended amount of sleep for pediatric populations: a consensus statement of the American Academy of Sleep Medicine. Journal of Clinical Sleep Medicine. 2016;12(6):785-786. pubmed.ncbi.nlm.nih.gov/27250809
- [9] Centers for Disease Control and Prevention. Child activity: an overview. cdc.gov
- [10] Centers for Disease Control and Prevention. Anthropometric indices: definitions and categories. cdc.gov
- [11] Centers for Disease Control and Prevention. Child and teen BMI categories. cdc.gov
- [12] Centers for Disease Control and Prevention. Using the BMI-for-age growth charts: what to know. cdc.gov
