Pediatric Growth Charts: WHO vs CDC vs Fenton, and How to Read Percentiles

Based on CDC recommendations for growth chart use, WHO growth standards, and the Fenton 2013 preterm growth chart. Updated July 2026.

Growth is the most repeated measurement in pediatrics, and the chart you plot it on matters as much as the number itself. Here is the map.

Which chart, at which age

• Birth to 24 months — WHO growth standards. The WHO charts describe how healthy, predominantly breastfed children should grow under optimal conditions. The CDC recommends them for all US children under 2.
• 2 to 19 years — CDC growth reference. From age 2, US practice switches to the CDC 2000 charts, which also add BMI-for-age — the standard screen for underweight, overweight, and obesity from age 2 onward.
• Preterm infants — Fenton chart. Babies born preterm are plotted on the Fenton preterm growth chart by postmenstrual age until about 50 weeks, then transition to standard charts using corrected age.

What a percentile actually says

A percentile is a ranking against a reference population of the same age and sex — nothing more. The 50th percentile is not a target, and the 10th percentile is not a deficiency. A small child tracking steadily along the 10th percentile is usually growing normally; the signal to look closer is a change in trajectory, classically crossing two or more major percentile lines, or measurements falling outside the extreme bands.

Corrected age, briefly

For a preterm infant, subtract the weeks of prematurity from the chronological age before plotting: a 6-month-old born at 32 weeks (8 weeks early) is plotted at 4 months corrected. This is standard until about 24 months of age.

Plot it properly

Open the Growth Percentile Calculator →

It computes exact percentiles and z-scores against the WHO, CDC, and Fenton references, handles corrected age for preemies, and charts the trend across visits.

Frequently asked questions

Which growth chart should be used at which age?

WHO standards from birth to 24 months, CDC reference from 2 to 19 years, and the Fenton chart for preterm infants until roughly 50 weeks postmenstrual age.

What does a growth percentile mean?

It is the child's position relative to a reference population of the same age and sex — a steady percentile in the normal range is healthy at any line.

When should corrected age be used?

For preterm infants, until about 24 months of age, for both growth plotting and developmental assessment.

Is crossing percentile lines a problem?

Trend beats any single point. Crossing two major lines is a common trigger for evaluation, though some shift is physiologic in the first 2–3 years.

Sources: CDC recommendations on WHO/CDC growth chart use; WHO Child Growth Standards; Fenton TR & Kim JH, BMC Pediatrics 2013. For clinical decision support and education only — not a substitute for clinical judgment.