A person can find an age-based height and weight chart for children online at the United States Centers for Disease Control and Prevention and Baylor College of Medicine. In addition to charts that relate, age, height and weight, there also are charts and tools for children's body mass index, or BMI. The BMI can help to identify a child that has a weight problem.
The charts available are for both girls and boys up to 20 years of age. There are length-for-age and weight-for-age charts for infants. Other charts are for the age group of 2 to 20 years and preschoolers.
The Baylor College of Medicine offers tools that a person can use to input a child's age, gender, height and weight, and this data is used for BMI information. This data is depicted on a graph, and ranking is given in percentiles. A child who is in the 95th percentile is considered obese.