Medical Disclaimer

Child Growth Lab provides educational information, reference comparisons, and arithmetic calculations. It is not a hospital, clinic, telehealth service, or healthcare professional, and use of the site does not create a clinician–patient relationship.

The site does not provide individualized medical advice or diagnose, treat, or prevent disease. It does not decide whether a child is normal or abnormal, or determine testing, referral, medication, treatment, feeding plans, or calorie targets. Do not start, stop, or change medical care solely because of a website result.

• Percentile:a position relative to a specific reference population, age, sex-specific chart, and measurement. A percentile is not a diagnosis, health score, or ranking of a child's worth.
• z-score: a statistical expression of distance from a reference distribution. It is not a diagnosis or a direct measure of disease severity.
• BMI category: a screening classification. It cannot by itself describe overall health, body composition, cause, or treatment need.
• % of P95: a comparison between BMI and the age- and sex-specific P95 BMI. It is not a BMI percentile or a percentage above a normal value.
• BIV flag: a technical signal to review an extreme value, measurement, or entry. It is not a diagnosis and does not automatically prove the data are wrong.
• Growth velocity is arithmetic change between two dated measurements. The site does not implement an age-specific velocity percentile or diagnostic threshold.
• Corrected age: date arithmetic for preterm context. It does not change a birthday or legal age, independently change vaccination timing, automatically select a chart, or determine when correction should stop.
• Mid-parental height: a rough family-height background reference. A mid-parental range is not a guarantee, certain adult-height prediction, or individualized prediction interval.

Results depend on accurate inputs. Errors in dates, units, age, sex-specific reference selection, or measurement method can change an output. Home measurements can vary with equipment, posture, clothing, time of day, and how a reading is taken.

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 difference, date change, or display rounding can change a category or reference position. Output precision cannot exceed the quality of the input or source data.

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.

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. Reference charts describe population distributions; they do not identify a cause.

A calculator cannot combine the complete medical history, physical examination, laboratory or imaging findings, development, nutrition, family environment, and local clinical practice that may matter for an individual child.

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.

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

Contact an appropriate healthcare professional with concerns about growth, nutrition, development, puberty, preterm history, or health. A professional can consider repeat measurements, longitudinal patterns, medical history, examination, family background, development, nutrition, and any necessary tests.

This site cannot decide whether a visit, test, or referral is needed. Use local emergency medical services for an urgent or acute concern. Do not send emergency requests or complete medical records to the support inbox. The Contact page explains safe issue reporting, and the Privacy Policy explains data and email boundaries.