Many parents wonder whether their child is at a healthy weight. Your pediatrician or healthcare provider will likely use a growth chart to monitor your child's weight and height at each office visit. While each young person is different, there are established ranges of normal weight based on a child's age, sex and height. The Centers for Disease Control and Prevention (CDC) provides reference charts to monitor and assess weight in children from age 2 to 20 years.
CDC provides weight-for-age growth charts for boys and girls aged 2 to 20. The 5th and 95th percentiles on these charts are generally considered the outermost limits for a child who is growing normally. Based on age and sex alone, the CDC growth charts indicate that a 7-year-old boy weighing 41 to 68 pounds is within the 5th to 95th percentile range. The 50th percentile for 7-year-old boys is 51 pounds. This means half of healthy boys this age weight less than 51 pounds and half weigh more. A 7-year-old girl weighing 40 to 69 pounds is within the 5th to 95th percentile range, according to CDC's growth charts. The 50th percentile for 7-year-old girls is 50 pounds.
Body Mass Index
Just as it is for adults, height is a major consideration in determining whether a child's weight is within a healthy range. For this reason, CDC recommends using body mass index (BMI) to determine whether a child's weight is normal. BMI takes into account both the height and weight of the child. Separate charts are used for boys and girls aged 2 to 20, as a child's sex also influences healthy BMI ranges.
Interpretation of BMI differs for children and adults. BMI charts for children use ranges based on percentiles to determine whether a youngster is underweight, overweight or normal for the child's age. A BMI between the 5th and 85th percentile is considered normal for children aged 2 to 20. For a 7-year-old boy, this is a BMI of approximately 13.7 to 17.4, with a 50th percentile value of 15.5. For a 7-year-old girl, the 5th to 85th percentile range is approximately 13.5 to 17.6, with a 50th percentile value of 15.4.
Talk with your child's healthcare provider if you have concerns about your child's weight. While weight ranges based on age-based growth and BMI charts can help identify a weight problem, each child is different and there may be other factors to consider in determining whether your child's weight is within a healthy range. If your child is deemed underweight or overweight, your healthcare provider can make recommendations to help get your youngster back on track.
Reviewed and revised by: Tina M. St. John, M.D.