WHO growth chart calculator
See the WHO reference midpoint from age and sex, then add any measurements you have to calculate their percentiles.
WHO growth reference instrument
Date of birth is the only field you need to see the reference midpoint.
The method
Weight is converted to kilograms, and length plus head circumference are converted to centimeters before the LMS lookup.
Age-based indicators use age in months from UTC-safe day math. Weight-for-length uses recumbent length in centimeters.
The calculator uses the CDC LMS formula and a local Gaussian CDF. No CDC or WHO runtime request is made.
Trust & methodology
The data is bundled from official CDC WHO Growth Charts files, and the page keeps chart boundaries visible for parents and caregivers.
Last sitewide review
June 11, 2026
Maintained by
Baby Milk Calculator editorial team
Editorial policy
Who writes the site, how sources are chosen, how updates and corrections are handled.
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How we calculate
The intake ranges, unit conversions, and guardrails behind every result.
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Corrections & contact
Send a question or correction to support@milkcalculator.org.
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Growth chart guide
01
A percentile places one measurement on a reference curve. For example, a weight-for-age percentile compares a baby's weight with babies of the same sex and age in the WHO reference. One measurement is a snapshot; growth over time is the more useful pattern to review with a pediatrician.
02
This calculator uses the WHO Child Growth Standards for birth through 24 months, using the CDC-hosted LMS data files for weight-for-age, length-for-age, head circumference-for-age, and weight-for-length.
03
Under age 2, the expected measurement is recumbent length: the baby is measured lying down. CDC training notes that switching from recumbent length to a standing measurement can shift chart interpretation, so this page uses length throughout.
04
CDC growth-chart training states that BMI-for-age is not recommended for children younger than 2 years. Weight-for-length is the included size comparison for this age range.
05
Ask your pediatrician about measurements that are hard to take, sudden percentile shifts, feeding concerns, low diaper output, or a result that does not match what you are seeing at home. If your baby seems very ill, dehydrated, hard to wake, or has trouble breathing, seek urgent medical care.
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FAQ
It uses WHO Child Growth Standards LMS values published through the CDC's WHO Growth Charts data files for babies from birth through 24 months.
For children younger than 2 years, CDC guidance uses recumbent length measured lying down. Keep the same measurement method when comparing results over time.
CDC growth-chart training notes that BMI-for-age is not recommended for children younger than 2 years, so this calculator uses weight-for-length instead.
Use it as a discussion aid only. Premature babies may need corrected-age tracking or an individualized growth plan from their pediatrician or NICU team.
No. Percentiles are tracking points. A pediatrician looks at measurement accuracy, trend over time, feeding history, medical history, and the full clinical picture.
References
CDC / National Center for Health Statistics
CDC-hosted WHO LMS data files for weight-for-age, length-for-age, head circumference-for-age, and weight-for-length charts.
CDC Growth Chart Training
CDC guidance on using WHO growth standards for U.S. children from birth to 2 years.
World Health Organization
WHO documentation and standards for child growth indicators, including length, weight, and head circumference.
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