CDC Growth Charts (2-20 Years)
Weight-for-Age (2-20)
z = (W − μ) / σ
Weight percentile against CDC 2-20 year reference.
Calculate Percentile →Stature-for-Age (2-20)
z = (H − μ) / σ
Standing-height percentile through adolescence.
Calculate Percentile →Weight-for-Stature (2-20)
z(W | H)
Size-adjusted weight screen — age-independent.
Calculate Percentile →Extended BMI-for-Age (2-20)
BMI = W / H²
CDC Extended BMI chart with severe-obesity differentiation.
Calculate Percentile →The CDC 2-20 year growth charts are the standard U.S. reference for children and adolescents from age 2 through 20. The Extended BMI-for-Age chart (added 2022) extends BMI percentiles beyond the 97th percentile to cover severe obesity classifications that the original chart compressed at the 97th percentile asymptote.
Each calculator returns the CDC-referenced percentile, z-score, and a visual placement on the CDC curves. The Extended BMI chart specifically displays adjusted percentiles beyond the original 97th-percentile ceiling.
When to use these calculators
These charts are the U.S. standard for ages 2-20 in pediatric primary care, school health, and obesity screening. The Extended BMI chart is the recommended reference for evaluating severe obesity in children, replacing the prior practice of reporting 'BMI > 99th percentile' without further differentiation.
Frequently Asked Questions
- What is the Extended BMI chart?
- Released in late 2022 by the CDC, it extends the BMI-for-age curves beyond the 97th percentile using a modeled extension. It enables clinical differentiation of class 2 and class 3 obesity in pediatric populations, which the original chart could not.
- When do U.S. clinicians transition from CDC 0-3 to CDC 2-20?
- Between 24 and 36 months — there's intentional overlap so the transition can happen at a routine well-child visit without re-plotting a different chart at every measurement.
- Is the 2-20 chart sex-specific?
- Yes — every CDC growth chart, including the 2-20, is sex-specific. The boys' and girls' curves diverge especially after age 10 as puberty timing differs.