Pediatric growth chart calculators

Start with these high‑value pediatric growth calculators, then explore the focused sections below for clinical reminders and counseling tips.

• Pediatric BMI calculator — body mass index before percentile interpretation.
• BMI percentile calculator — screening for underweight/overweight trends.
• Height percentile calculator — stature tracking over time.
• Weight percentile calculator — baseline growth and weight velocity.
• Head circumference percentile — infant brain growth monitoring.
• Adjusted (corrected) age calculator — preterm growth tracking.
• Gestational age calculator — PMA and preterm dating.
• Fenton growth chart — Fenton 2025 vs 2013 chart chooser.
• Fenton 2013 vs 2025 — preterm chart-version comparison.
• Fenton 2013 growth calculator — legacy preterm chart workflow.
• Fenton 2025 growth calculator — preterm PMA and chart handoff.
• Olsen 2010 growth calculator — U.S. size-at-birth curves for preterm infants.
• Olsen 2015 BMI calculator — BMI curves for preterm infants.
• CDC growth calculator 0 to 36 months — CDC infant chart percentiles and z-scores.
• CDC growth calculator 2 to 20 years — CDC child and teen percentiles, z-scores and BMI.
• WHO growth calculator 0 to 24 months — WHO infant percentiles and z-scores.

Order reflects common growth‑percentile workflow and clinical follow-up needs.

Use this hub as a growth-tools index: start with the immediate measurement question, then open the supporting calculator when interpretation depends on age, sex, family height, or prematurity.

• BMI screening
  Pediatric BMI calculator then CDC growth calculator 2 to 20 years.

  Calculate BMI first, then use age- and sex-specific percentile interpretation for children and teens.

• Linear growth
  Height percentile calculator then Mid-parental height calculator.

  Pair current height percentile with family target height when short or tall stature needs context.

• Weight trend
  Weight percentile calculator then BMI percentile calculator.

  Review weight-for-age alongside BMI when nutrition, illness, or growth velocity is the question.

• Infant head growth
  WHO growth calculator 0 to 24 months then CDC growth calculator 0 to 36 months.

  Track head circumference with weight and length so infant growth patterns stay symmetric.

• Preterm growth
  Gestational age calculator then Fenton growth chart.

  Use corrected age and preterm chart context before moving former preterm infants onto term charts.

• Confirm age units (months vs. years) and measurement units (cm vs. inches, kg vs. lb).
• Use serial measurements to assess growth velocity instead of relying on a single visit.
• Interpret results with feeding history, pubertal stage, chronic disease, and family growth patterns.

Small measurement errors can meaningfully shift percentiles, especially in infants. Use consistent technique and calibrated scales or stadiometers whenever possible.

Height and weight percentiles describe how a child compares to peers of the same age and sex. BMI percentile incorporates weight and height to screen for underweight, overweight, and obesity in children 2 years and older.

Percentiles should be interpreted as trends. A stable percentile band over time often reflects healthy growth, while a persistent downward shift or rapid acceleration may warrant further evaluation.

• Height percentile calculator
• Weight percentile calculator
• BMI percentile calculator
• CDC growth calculator 2 to 20 years when the chart source must stay CDC for all metrics.

• Confirm age boundaries for BMI percentile (typically 2–20 years).
• Document clothing/diaper adjustments for accurate infant weights.
• Consider pubertal stage and athletic build when interpreting BMI percentiles.

If the BMI percentile is high, focus on nutrition quality, activity, and sleep habits before making assumptions about health risk. Counseling is most effective when framed around healthy routines rather than a target number.

Head circumference percentiles are most useful in infants and toddlers, where brain growth is rapid. Track head circumference alongside length and weight to evaluate overall growth symmetry.

Measurement technique matters: the tape should wrap around the occiput and the most prominent part of the forehead. Even small errors can shift percentiles in early infancy.

• Head circumference percentile calculator
• WHO growth calculator 0 to 24 months for routine infant weight, length, head, BMI, and weight-for-length context.

• Recheck if the percentile is unexpectedly high or low.
• Look for crossing percentile lines or changes in head shape.
• Document the measurement method for repeatability.

Sudden shifts in head circumference percentiles warrant prompt evaluation, especially when accompanied by neurologic symptoms or developmental concerns.

Corrected (adjusted) age helps align preterm infants with developmental and growth milestones. It is calculated by subtracting the weeks of prematurity from chronologic age.

Preterm charts such as Fenton 2013 run to 50 weeks postmenstrual age, where they join the WHO growth standard. After the switch, plot former preterm infants on WHO charts at corrected age. Follow local NICU or outpatient guidance for the exact timing of that transition.

• Adjusted (corrected) age calculator
• Gestational age calculator for PMA, EDD, corrected age, and day-of-life documentation.

• Document gestational age at birth when calculating corrected age.
• Use corrected age for growth and developmental assessments in early infancy.
• Note the chart source (WHO, CDC, or preterm-specific) in documentation.

Clear documentation of corrected age helps avoid unnecessary referrals and reassures families when growth is appropriate for prematurity.

For preterm infants, use corrected age plus preterm chart context before interpreting growth against term WHO or CDC curves. Fenton and Olsen chart references can help bridge early preterm follow-up before the child transitions to term growth charts.

• Adjusted age calculator for corrected-age setup.
• Gestational age calculator for PMA and preterm dating.
• Fenton growth chart for choosing 2025 vs 2013 and official chart handoffs.
• Fenton 2013 vs 2025 for chart-version transitions and trend notes.
• Fenton 2013 growth calculator for legacy Fenton chart handoff.
• Fenton 2025 growth calculator for PMA and official chart handoff.
• Olsen 2010 growth calculator for U.S. preterm size classification context.
• Olsen 2015 BMI calculator for preterm BMI-for-age context.
• CDC growth calculator 0 to 36 months when the infant chart source must remain CDC.
• Fenton preterm growth chart reference for chart context.
• Weight percentile calculator once term chart interpretation is appropriate.

Document gestational age, corrected age, chart source, and transition timing so follow-up teams know which growth curve was used.

Mid‑parental (target) height offers a rough estimate of expected adult stature based on parental heights. It is a counseling tool, not a prediction, and should be combined with clinical context and growth trends.

When a child’s height percentile is far outside the target range, consider family history, chronic disease, endocrine conditions, and nutrition before making assumptions.

• Mid‑parental height (target height)

• Use accurate, measured parental heights when possible.
• Review growth velocity to distinguish familial short stature from pathology.
• Discuss the limits of prediction when counseling families.

Many families interpret percentiles as scores. Reframing percentiles as a comparison tool helps reduce anxiety and keeps the focus on healthy growth patterns.

• Use phrases like "trend line" or "growth curve" instead of "rank."
• Emphasize consistency across visits and overall health.
• Highlight practical steps: sleep, nutrition quality, activity, and routine follow‑up.

If a percentile is concerning, explain what will be monitored, what tests are needed, and how quickly changes are expected. Clear expectations reduce caregiver worry and improve follow‑up.

One accepted definition of failure to thrive is weight for age, or weight for length, that falls across two major percentile lines (95, 90, 75, 50, 25, 10 and 5) over time (Homan, Am Fam Physician 2016). On the WHO charts, CDC uses the 2nd and 98th percentile lines (2 standard deviations) to flag growth that may point to a health problem (MMWR 2010).

Before acting on a change, re-measure with the same technique and check that the same chart and the right (corrected) age were used. Weight, length and head circumference that move apart, or a growth change with symptoms such as ongoing vomiting, diarrhea or loss of skills, need a clinician's review.

• Grummer-Strawn LM, Reinold C, Krebs NF. Use of World Health Organization and CDC growth charts for children aged 0-59 months in the United States. MMWR Recomm Rep. 2010;59(RR-9):1-15.
• CDC. Clinical growth charts, 2-20 years.
• World Health Organization. WHO Child Growth Standards (0-5 years).
• Fenton TR, Kim JH. A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants. BMC Pediatr. 2013;13:59.
• University of Calgary. Fenton preterm growth charts (2025 third generation and 2013).
• Fenton 2025 third-generation preterm growth chart development paper. Paediatr Perinat Epidemiol. 2025.
• Olsen IE, Groveman SA, Lawson ML, Clark RH, Zemel BS. New intrauterine growth curves based on United States data. Pediatrics. 2010;125(2):e214-e224.
• Olsen IE, Lawson ML, Ferguson AN, et al. BMI curves for preterm infants. Pediatrics. 2015;135(3):e572-e581.
• Homan GJ. Failure to thrive: a practical guide. Am Fam Physician. 2016;94(4):295-299.