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Child Growth Lab

Pediatric growth calculators for WHO and CDC references, BMI, growth change, corrected age, and family-height context.

Use limits

Medical Disclaimer

Child Growth Lab provides educational information, reference comparisons, and arithmetic calculations. It does not provide medical care.

How to use a Child Growth Lab result

Use a result as one piece of information, not as a standalone medical decision. Child Growth Lab is not a hospital, clinic, telehealth service, or healthcare professional, and using the site does not create a clinician–patient relationship.

Results can help with

  • Reference comparison against the selected age, sex, and measurement standard.
  • Screening classification where the tool explicitly provides one.
  • Arithmetic calculations, timelines, and family-height context.
  • Preparing focused questions for an appropriate healthcare professional.

Results cannot by themselves

  • Diagnose disease, identify a cause, or determine a prognosis.
  • Determine treatment, testing, referral, feeding, medication, or calorie decisions.
  • Establish overall health or replace accurate measurements, history, or examination.

Do not start, stop, delay, or change medical care solely because of a calculator or guide result.

If a result surprises or worries you

  1. Recheck the dates, units, measurement method, and selected reference.
  2. Recheck the measurement when practical and appropriate.
  3. Read the specific tool's scope and limitations.
  4. For an actual health or growth concern, discuss the result with an appropriate healthcare professional.

The site cannot decide whether a visit, test, or referral is needed. For an urgent or emergency concern, use appropriate local emergency medical services rather than the website or support inbox.

What the common outputs mean

Reference positions

Percentile and z-score describe statistical position in a defined reference distribution. They are not disease severity scores, health grades, or diagnoses. A percentile is not a diagnosis.

Screening classifications

BMI category, % of P95, and a BIV/extreme flag support screening or technical review. They are not standalone diagnoses; a BIV flag is a technical review signal and does not automatically prove the measurement is wrong.

Arithmetic and context

Growth velocity is arithmetic change expressed as an arithmetic rate between dated comparable measurements. Corrected Age is timeline context, and a corrected-age result does not change a birthday. Mid-Parental Height is rough family-height context; a mid-parental range is not a guarantee, prediction, or treatment target.

When to speak with a professional

An appropriate healthcare professional can consider repeat measurements, longitudinal patterns, history, examination, family context, development, nutrition, and further evaluation when the situation calls for it. Do not request a particular test or referral solely from this page.

For an urgent or emergency health concern, use appropriate local emergency medical services. Do not email the support inbox for emergency help.

Measurement and input limitations

A calculator can calculate accurately from an inaccurate measurement. Results depend on accurate dates, units, age, sex-specific reference selection, and measurement method. Equipment, posture, clothing, time of day, and technique can affect a home reading.

Standing height and recumbent length are different measurement methods and must not be interchanged casually. Use each input only as the relevant calculator explains. Near a threshold, a small measurement or date difference can change a displayed category or reference position. Displayed precision cannot exceed input or source quality.

One measurement does not establish a growth trend. Change between two measurements can also reflect measurement error or a difference in method, not only biological change.

Chart, population, and clinical-context limitations

Growth charts are legitimate screening and monitoring references, but they are not intended to be the sole diagnostic instrument. They contribute to an overall clinical impression or picture; a chart position does not identify a cause.

WHO, CDC, and other methods have defined age, measurement, and reference-population scopes. Different charts, versions, measurement methods, or clinical purposes can produce different results. A general-population chart may not fit every preterm child or every genetic, syndromic, chronic, endocrine, nutritional, or other special clinical situation.

The site does not automatically select a specialized chart for every circumstance. Corrected-age use depends on the purpose of the assessment and clinical context; see theCorrected Age guide andMethodology for scope. A calculator cannot combine the complete medical history, physical examination, development, nutrition, family context, labs, imaging, and local clinical practice that may matter in an individual situation.

Calculator-specific limitations

CDC and WHO growth percentiles

These are reference comparisons, not diagnoses. One point does not replace a longitudinal pattern or clinical context.

BMI

BMI, BMI percentile, BMI category, and % of P95 are screening information. BMI is not a direct body-fat measurement or a standalone diagnosis of disease or overall health. Official category labels are not treatment decisions.

Growth Velocity

The arithmetic rate requires comparable dated measurements. A short interval or different measurement methods can mislead, and an annualized value is not a prediction. The site does not provide a velocity percentile or diagnostic threshold.

Corrected age

This is a timeline and context calculation. It does not change legal age, vaccination scheduling, or automatically select a growth chart; purpose-specific clinical guidance determines use.

Mid-Parental Height

This is a rough family-height background reference, not a guaranteed adult height, precise individualized prediction, treatment target, or diagnosis.

Accuracy, source updates, and availability

Child Growth Lab aims for accurate, transparent, and reproducible calculations. Content and methods draw on applicable official guidance, original data, professional-organization material, technical documentation, and primary research. Sources, formulas, boundaries, units, dates, and rounding receive internal review and tests intended to reduce error risk.

Those processes cannot ensure that every result is error-free, every page is complete, every source change is found immediately, every individual clinical context is covered, or the site is continuously available. A source organization may update a dataset, guideline, or webpage before this site completes a new review and release; the site does not claim real-time source monitoring or automatic source synchronization.

For an important decision, check the original sources linked by the relevant page and discuss the situation with an appropriate healthcare professional.

Professional and emergency care

Discuss concerns about growth, nutrition, development, puberty, preterm history, or health with an appropriate healthcare professional. The professional can decide what context and evaluation are appropriate; this site does not set referral thresholds or tell you which tests to request.

Use local emergency medical services for an urgent or acute concern. Do not send emergency requests or complete medical records to the support inbox. TheContact page explains safe issue reporting, and the Privacy Policyexplains data and email boundaries.

Independence, advertising, and corrections

CDC, WHO, AAP, PES, RCPCH, and other source names identify references or standards. They do not imply affiliation, approval, certification, or endorsement of Child Growth Lab.

Advertising may support site operation, but advertisers do not determine evidence sources, formulas, thresholds, result categories, safety warnings, conclusions, or correction decisions. Advertising must remain distinct from the main content.

Report a suspected calculation or content problem throughContact. SeeEditorial Review for the correction process, Privacy for data and email handling, Terms of Use for site rules, and About for identity and funding.

Medical disclaimer updated

The use boundaries and tool limitations on this page were updated on. This is a content-maintenance date, not the date of a review by a named doctor. No named clinician has completed a site-wide clinical review.

See Editorial Review for the evidence and release-review process and Methodologyfor calculator sources, formulas, and implementation scope.