The revised growth charts consist of 16 charts (8 for boys and 8 for girls). These charts represent revisions to the 14 previous charts, as well as the introduction of two new body mass index-for-age (BMI-for-age) charts for boys and for girls, ages 2 to 20 years.

Most of the specific differences between the revised charts and the original charts occur in the charts for infants, where national data were previously lacking. The revised head circumference charts also show some noticeable differences when compared to the earlier charts. Compared to the original infant charts that were based on primarily formula-fed infants, the revised growth charts for infants contain a better mix of both breast- and formula-fed infants in the U. S. population. (On average, since 1970 approximately one-half of children born in the United States are reported to have been breast fed at some point, and about one-third have been breast fed for 3 months or more.) The addition of the BMI charts is probably the single most significant new feature of the revised growth charts.

These BMI-for-age charts were created for use in place of the 1977 weight-for-stature charts. BMI (wt/ht2) is calculated from weight and height measurements and is used to judge whether an individual's weight is appropriate for their height. BMI is the most commonly used approach to determine if adults are overweight or obese and is also the recommended measure to determine if children are overweight. The new BMI growth charts can be used clinically beginning at 2 years of age, when an accurate stature can be obtained.

In recent years, BMI has received increased attention for pediatric use. In 1994, an expert committee charged with developing guidelines for overweight in adolescent preventive services (ages 11-21 years) recommended that BMI be used routinely to screen for overweight adolescents. In addition, in 1997 an expert committee on the assessment and treatment of childhood obesity concluded that BMI should be used to screen for overweight children, ages 2 years and older, using the BMI curves from the revised growth charts. BMI can also be used to characterize underweight (though no expert guidelines exist for the classification of underweight based on BMI).

Further information about the revision process can be found on the growth charts website.