How Does the Height and Weight Chart Work?

The height and weight charts offered by the Centers for Disease Control and Prevention list heights, weights and the percentile of people at or above that measurement for every age, up to 20 years old. People use these charts to track growth and compare height and weight with national averages. How a chart works varies depending on the chart, as multiple types of height and weight charts are available.

The CDC height and weight charts list height in inches and centimeters, and weight in pounds and kilograms. Each chart has lines for height and weight corresponding to the 5th, 25th, 50th, 75th and 95th percentiles at every age from 2 to 20. The CDC offers charts for boys and girls, and has separate charts for children from birth until 36 months.

The National Health Service has a height and weight chart for adults that uses color shades to indicate whether certain height and weight combinations are underweight, healthy, overweight, obese or very obese. This chart is closely related to body mass index, a number rating that indicates a person's health according to height and weight. Body mass index and height and weight charts are sometimes inaccurate, as they can classify a healthy person as overweight if he has a large amount of muscle mass.