WHO vs CDC Growth Charts: What's the Difference?
Source: CDC, WHO, NHS/RCPCH | Last reviewed: April 2026
If you have ever looked up your child's growth measurement online, you may have seen different percentile results from different tools. The reason is often simple: different tools use different growth charts. The two most widely used internationally are the WHO Child Growth Standards and the CDC Growth Charts.
Here is a plain-English comparison.
WHO Growth Charts
The World Health Organization (WHO) Child Growth Standards were published in 2006, based on the Multicentre Growth Reference Study (MGRS). The study followed approximately 8,500 children from birth to age 5 in six countries: Brazil, Ghana, India, Norway, Oman, and the United States.
Children in the study were selected specifically because they were:
- Breastfed for at least 12 months
- Not exposed to smoke
- Living in environments without economic or health barriers to growth
The intent: WHO charts show how children should grow under optimal conditions. They represent a prescriptive standard — a reference for healthy growth worldwide.
WHO also published the WHO Growth Reference for 5–19 year olds (2007), which extends coverage to adolescence based on reconstructed and reanalysed data.
CDC Growth Charts
The CDC Growth Charts were published in 2000 (revised from earlier versions). They are based on data from several US national surveys conducted between 1963 and 1994, covering children aged 0–20 years.
The intent: CDC charts describe how US children actually grew during that period. They represent a descriptive reference — a snapshot of a particular population — rather than an optimal standard.
Key Differences
| Feature | WHO Charts | CDC Charts |
|---|---|---|
| Published | 2006 (revised WHO Multicentre data) | 2000 (US national survey data) |
| Age range | 0–5 years (primary); 5–19 with WHO Growth Reference | 0–20 years |
| Based on | Children in optimal conditions across 6 countries | Representative US population, 1963–1994 |
| Breastfeeding | Yes — breastfeeding was a requirement | Mixed feeding practices |
| Purpose | Prescriptive (how children should grow) | Descriptive (how US children did grow) |
| BMI charts | Yes | Yes |
| Head circumference | Yes (0–5) | Yes (0–36 months) |
Which Chart Is Used Where?
| Country | Under 2 | 2–5 Years | 5+ Years |
|---|---|---|---|
| United Kingdom | UK-WHO (RCPCH) | UK-WHO | UK-WHO |
| United States | WHO (AAP recommendation) | CDC recommended; WHO also used | CDC |
| Canada | WHO | WHO | WHO (5–19) |
| Australia | WHO | WHO / clinical context | CDC / WHO depending on setting |
UK note: The UK uses the UK-WHO charts — a version of the WHO charts adapted for the UK population, covering 0–18 years. These are the charts in your child's red book.
USA note: The CDC officially recommends its own charts for children 2 and older, but the American Academy of Pediatrics recommends WHO charts for all children under 2. In practice, most US paediatricians use the CDC charts for routine checkups for children aged 2+.
Does the Chart Choice Affect the Percentile?
Yes — especially for infants. Because WHO charts are based on breastfed children in optimal conditions, they can produce different percentile results than CDC charts for the same measurement.
A breastfed infant may look average or above average on WHO charts, but slightly below average on CDC charts (since CDC data includes more formula-fed infants who grew faster in the early months of life).
For older children (5+), the differences are smaller in practice, though the underlying data sources remain different.
Which Chart Should You Use Online?
If you are using a growth calculator or checking percentiles yourself, check which chart the tool uses. Our Child Growth Calculator uses simplified reference ranges for general awareness — not as a substitute for a professional assessment using the specific chart your healthcare provider uses.
For a clinically meaningful result, ask your child's health professional which chart they use and refer to those values. The percentile your health visitor or paediatrician plots is the one that matters for monitoring your child's growth over time.
The Bottom Line
- Both charts are valid tools used by healthcare professionals worldwide
- The WHO charts are based on children raised under optimal conditions — they are an international standard, especially for children under 5
- The CDC charts describe how US children grew historically and are the primary reference for US paediatric practice for ages 2–20
- The UK uses adapted UK-WHO charts from birth to 18
- For any concern about your child's growth, the most important step is to discuss it with your health professional, who will use the chart appropriate for your child's age and country
Related Guides
- What Is a Growth Percentile? — a plain-English explanation
- Understanding Child Growth Charts for Parents — how to read a growth chart
- Child Growth Calculator — quick growth reference tool
- When to See a Paediatrician About Growth — when to seek professional review
This guide is for general information only. Chart versions and clinical recommendations may be updated by health authorities. Always use the growth chart recommended by your child's healthcare provider.