CDC vs WHO Growth Charts
Parent GuideA quick, practical explainer of when to use WHO (0–24 months) and CDC (24 months+), why percentiles differ, and how to track your child’s growth consistently.
Why two growth chart systems?
WHO and CDC charts are both valid—but created for different purposes. WHO built a global standard for early life, reflecting optimal growth under ideal conditions; CDC built a US reference for older children and teens. Different cohorts and smoothing methods lead to small differences in cutoffs.
When to use which
- WHO: Ages 0–24 months (includes head circumference).
- CDC: Ages 24 months+ (includes BMI-for-age).
How percentiles work (LMS, in plain English)
Percentiles compare your child with peers of the same age and sex. Curves are generated via LMS smoothing so they’re stable at each age point. The trend over time matters more than any single reading.
Why numbers can differ
Because the underlying populations and methods differ, the 50th percentile for a given age might be slightly different between WHO and CDC. That’s normal—just stay consistent within one system for tracking.
How MyBabyGuide handles the split
- Our Growth Chart Calculator uses WHO for 0–24 months and CDC for 24+ months automatically.
- Age-specific guides show real cutoffs (10th/25th/50th/75th/90th) pulled from the official datasets.
- Child Height Predictor gives a parent-based baseline adjusted by the child’s current percentile.
Next steps
- Explore WHO growth percentiles (0–24 months) and CDC growth percentiles (2–20 years).
- Track your child over time with the Growth Chart Calculator.