Teen BMI Calculator: Exact CDC Percentile & Z‑Score (13‑19y)
CDC‑based tool for adolescents 13‑19. Get precise percentile rank, Z‑score, growth chart, and track changes over time.
Last clinical review: June 2026. Always consult a pediatrician.
1. Enter Teen Details
Results for Your Teen
BMI
—
Exact Percentile
—
Z‑Score
—
Category: —
BMI Percentile Chart (CDC 2000)
5th, 50th, 85th, 95th percentiles. Red dot = teen's BMI.
Disclaimer: Percentiles are interpolated from CDC 2000 growth charts. For medical decisions, always consult a pediatrician.
2. Growth Tracking & History
Last 10 calculations. Click any entry to see BMI trend over time.
Special Populations & Mental Health
Athletic teens: BMI may overestimate body fat. Consider body fat percentage for better insight.
Chronic illness / disability: BMI may not reflect overall health; always follow your specialist’s advice.
Transgender teens: Use affirmed gender for percentile; discuss with a gender‑affirming provider.
Pregnancy/breastfeeding: This tool is not applicable. See pregnancy BMI calculator.
Eating disorder warning signs: Rapid weight loss, skipping meals, excessive exercise, body dissatisfaction. Resources: NEDA Helpline (1‑800‑931‑2237).
Talking about weight: Focus on health behaviors, never shame. Encourage body neutrality and self‑respect.
Frequently Asked Questions
What is a healthy BMI percentile for a teen?
5th‑84th percentile (CDC). Below 5th = underweight, 85th‑94th = overweight, ≥95th = obesity.
How do you calculate exact percentile and Z‑score?
We interpolate between the 5th, 50th, 85th, and 95th percentiles using a smooth piecewise linear method, then convert the percentile to Z‑score via the inverse normal CDF.
What should I do if my teen is overweight/obese?
Avoid dieting. Focus on family meals, active hobbies, reduced screen time, adequate sleep. Consult a pediatrician for non‑stigmatizing support.
Can muscular teens have a high BMI but be healthy?
Yes. BMI does not measure muscle. Consider waist‑to‑height ratio and body composition.
How often should I check my teen’s BMI?
Annually at well‑teen visits, or more often if monitoring a treatment plan.