Child BMI Percentile Calculator: CDC Growth Chart Percentile for Ages 2 to 19 with Z-Score, Healthy Range and LMS Method
Built and reviewed by David (MBA Finance) · Updated August 2026
The most precise free child BMI percentile calculator in the US. Uses the CDC’s official LMS (Lambda-Mu-Sigma) statistical method, the same approach used in clinical pediatric practice, to calculate your child’s exact BMI-for-age percentile, Z-score, and CDC category. Covers all children ages 2 to 19, with age input in years and months for greater precision than year-only tools. Shows the healthy BMI range at your child’s exact age and sex, with PDF report and WhatsApp share. Always confirm results with your child’s pediatrician.
📊 LMS Statistical Method📐 Age in Years and Months🧮 Z-Score Output⚖️ Imperial and Metric📏 Healthy Range at Exact Age🩺 Pediatrician Notes Included
Child’s Age (2 to 19 years)
yrs
mos
For children under 2 years, use the Toddler BMI Calculator. The CDC uses separate growth charts for children under 2 and those aged 2 and older.
Sex
The CDC uses separate sex-specific BMI-for-age growth charts for boys and girls. Sex is required for accurate percentile calculation.
Height
ft
in
Weight
lbs
Height
cm
Weight
kg
📊 BMI Percentile Results
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Enter your child’s age (years and months), sex, height and weight, then click Calculate Percentile. You’ll see their BMI-for-age percentile, CDC growth chart category, Z-score, and healthy BMI range for their exact age and sex. Always share these results with your child’s pediatrician.
Percentile
BMI Score
Z-Score
Age
🩺 Important: BMI percentile is a screening tool, not a diagnosis. Always discuss your child’s BMI result with their pediatrician, who can evaluate it in the context of growth history, development, and overall health.
CDC BMI-for-Age Percentile Categories
Child BMI Percentile Charts: CDC Growth Chart Categories for US Children Ages 2 to 19
Unlike adult BMI, which uses fixed numerical cutoffs (18.5, 25.0, 30.0) that apply identically to every person aged 20 and older, child BMI is interpreted as a percentile relative to same-age, same-sex peers. The CDC’s BMI-for-age percentile charts compare a child’s BMI to the distribution of BMI values observed in a large national reference population of US children, showing what percentage of children of the same age and sex have a lower BMI. A child at the 65th percentile has a BMI higher than 65% of children of the same age and sex in the US reference population.
This percentile approach is used because children’s normal body composition changes substantially as they grow: what constitutes a healthy BMI for an 8-year-old is very different from what constitutes a healthy BMI for a 16-year-old of the same sex, and using a single fixed threshold (like adult BMI) would misclassify millions of healthy growing US children.
The CDC defines four BMI-for-age weight status categories for US children aged 2 to 19. Underweight means a BMI-for-age below the 5th percentile: fewer than 5% of same-age, same-sex US children in the reference population have a lower BMI. Healthy Weight means a BMI-for-age at or above the 5th percentile and below the 85th percentile. Overweight means a BMI-for-age at or above the 85th percentile and below the 95th percentile. Obese means a BMI-for-age at or above the 95th percentile. These thresholds were established by the American Academy of Pediatrics (AAP) and the CDC in the late 1990s based on epidemiological research linking BMI-for-age percentile ranges with health outcomes in US children, and they remain the standard used by US pediatricians today. The CDC’s official clinical growth charts are available at cdc.gov/growthcharts.
CDC Category
Percentile Range
Interpretation
Follow-Up
Underweight
Below 5th percentile
Lower BMI than 95% of peers
Discuss with pediatrician
Healthy Weight
5th to below 85th
In the healthy range for age and sex
Routine wellness visits
Overweight
85th to below 95th
Higher BMI than most peers
Discuss with pediatrician
Obese
95th percentile and above
Higher BMI than 95% of peers
Pediatric evaluation recommended
How This Child BMI Percentile Calculator Uses LMS Statistics and CDC Reference Data
This calculator implements the CDC’s LMS (Lambda-Mu-Sigma) statistical method for computing exact BMI-for-age percentiles, the same method used in clinical pediatric software and the CDC’s own published growth chart analysis tools. The LMS method works by characterizing the distribution of BMI at each age and sex with three parameters: L (a Box-Cox power transformation coefficient that corrects for skewness in the distribution), M (the median BMI at that age and sex), and S (the coefficient of variation). These parameters are published by the CDC for each age in months for children ages 2 to 19. The calculator uses LMS values at whole-year intervals with linear interpolation for the child’s specific months of age beyond the last full year, providing accurate results for children reported in years and months rather than just years.
This month-level precision matters for growing children because BMI-for-age percentiles can shift meaningfully within a single year as a child grows taller.
Once L, M, and S values are identified for the child’s age and sex, the BMI Z-score is calculated using the formula: Z equals (BMI divided by M, raised to the power L, minus 1) divided by (L times S). This Z-score represents the number of standard deviations the child’s BMI falls above or below the median for children of the same age and sex. A Z-score of 0 means the child is at exactly the 50th percentile; a Z-score of 1.0 corresponds to approximately the 84th percentile; a Z-score of -1.0 corresponds to approximately the 16th percentile. The percentile is then calculated from the Z-score using the Abramowitz and Stegun approximation of the normal cumulative distribution function, which has a maximum error of less than 7.5 ten-millionths across the full range. The result is equivalent to the output of clinical-grade pediatric BMI software used in US physician offices.
Three US Children BMI Examples: School-Age, Tween and Teen Percentile Calculations
Columbus, OH: 8-Year-Old Boy
Height 4’6″, Weight 78 lbs
BMI17.2
CDC 50th pct BMI at 8y16.2
Z-score+0.60
PercentileApprox. 73rd
CDC CategoryHealthy Weight
Pediatrician noteRoutine follow-up
Portland, OR: 12-Year-Old Girl
Height 5’1″, Weight 130 lbs
BMI24.6
CDC 50th pct BMI at 12y19.3
Z-score+1.40
PercentileApprox. 92nd
CDC CategoryOverweight
Pediatrician noteDiscuss at next visit
Denver, CO: 16-Year-Old Boy
Height 5’10”, Weight 162 lbs
BMI23.3
CDC 50th pct BMI at 16y21.1
Z-score+0.60
PercentileApprox. 72nd
CDC CategoryHealthy Weight
Pediatrician noteRoutine follow-up
BMI Percentile Interpretation: What the Numbers Mean for Your Child’s Health
Understanding what your child’s BMI percentile means requires important context that goes beyond the single number. The percentile shows where your child falls relative to a national reference population of US children from the late 1980s and early 1990s (the data period for the CDC 2000 Growth Charts), not relative to today’s US children, who have higher average BMI values due to changes in diet, activity, and body composition trends over the past 30 years. This matters because a child at the 85th percentile is above 85% of the 1990s reference population, but may be closer to the median of their actual current school or community. The reference population comparison is still clinically meaningful because the long-term health outcome data (associating BMI-for-age percentile with disease risk) was collected using these same reference charts.
A single BMI percentile value is a snapshot in time. Pediatricians use BMI-for-age tracking across multiple visits to identify trends: a child consistently at the 60th percentile showing concern is one whose trajectory is moving steadily upward (perhaps from the 45th to 55th to 65th percentile over 3 years) rather than staying stable. US pediatric guidelines from the American Academy of Pediatrics recommend plotting BMI on growth charts at every well-child visit from age 2 onward, enabling pattern recognition that a one-time online calculation cannot provide. If you use this calculator and receive a result in the overweight or obese range, the single most important action is to schedule a conversation with your child’s pediatrician, who can review their complete growth history and determine whether clinical follow-up is warranted.
For underweight results, pediatric follow-up is also important to rule out nutritional concerns or underlying health conditions.
When to Be Concerned About a Child’s BMI Percentile
US pediatric guidelines identify several BMI-for-age patterns that warrant medical attention. A child whose BMI percentile has increased by more than 10 to 15 percentile points in a single year warrants evaluation even if still in the healthy range, as rapid upward trajectories predict future overweight status. A child crossing the 85th percentile threshold for the first time warrants a pediatric assessment that typically includes family history review, blood pressure, and sometimes fasting blood glucose and lipid panel, since these metabolic markers can be abnormal in children with overweight BMI even if they feel healthy.
A child in the obese range (95th percentile and above) qualifies for comprehensive pediatric obesity management per the 2023 American Academy of Pediatrics Clinical Practice Guideline on Pediatric Obesity, which recommends intensive health behavior and lifestyle treatment. Underweight children (below the 5th percentile) warrant evaluation for nutritional adequacy, disordered eating, or underlying medical causes.
01
Track Percentile Trajectory Over Time, Not Just the Single Number
A child at the 70th percentile who was at the 55th percentile two years ago is showing upward trajectory that deserves attention, even though 70th percentile is technically in the healthy range. A child at the 88th percentile who has been stable between the 85th and 90th for three years is showing a much more reassuring pattern than those numbers alone suggest. The trajectory (direction and rate of change) is what US pediatricians evaluate most carefully when reviewing growth charts across visits, not a single data point. Use this calculator at each of your child’s well-child visits to track their percentile over time, and bring the results to your pediatrician for context within their complete growth record. The CDC’s free growth chart PDF tools at cdc.gov/growthcharts allow parents to plot multiple BMI values over time on the same chart for a visual trend.
02
Accuracy of Measurement Matters More for Children Than Adults
Children’s BMI percentile results are more sensitive to measurement error than adult BMI because the percentile curves for children are steeper (a 1-pound or half-inch difference can shift the percentile meaningfully at some ages). When measuring at home, use a digital scale on a hard floor (not carpet) and measure the child’s height against a flat wall with the child standing without shoes, head straight, heels touching the wall. Pediatrician offices use calibrated balance-beam scales and stadiometers that are more accurate than most home equipment. If your home measurement gives a percentile near a category boundary (such as near the 85th or 95th percentile), have the pediatrician’s office measure the child at the next well-child visit and use the clinical measurements for category determination. This calculator accepts fractional inches and half-pounds for greater precision in home measurements.
03
BMI Percentile Is One Component of a Child’s Complete Health Picture
BMI-for-age percentile tells you a child’s weight relative to height relative to peers, nothing more. It does not measure fitness, muscle mass, bone density, dietary quality, sleep, mental health, or any of the other factors that contribute to a child’s complete wellbeing. US pediatric research has consistently found that physically active children with overweight BMI percentiles have better cardiovascular health markers than sedentary children with healthy weight percentiles. Conversely, children with normal weight percentiles can have poor diets, low physical activity, and metabolic risk factors that BMI does not detect. The American Academy of Pediatrics recommends that conversations about weight in children focus on healthy behaviors (daily physical activity, fruit and vegetable intake, adequate sleep, screen time limits) rather than on BMI numbers themselves, to support positive body image and healthy development across all percentile levels.
Healthy BMI Ranges for US Children by Age and Sex
The table below shows the BMI values corresponding to the 5th (lower healthy bound) and 85th (upper healthy bound) percentile boundaries for boys and girls at key ages. Any BMI between these two values falls in the CDC healthy weight category for that age and sex. These reference values are derived from the CDC LMS parameters used in this calculator.
Age
Boys 5th pct BMI
Boys 50th pct BMI
Boys 85th pct BMI
Girls 5th pct BMI
Girls 50th pct BMI
Girls 85th pct BMI
4 years
13.8
15.3
16.9
13.5
15.0
16.8
6 years
13.8
15.5
17.4
13.5
15.4
17.7
8 years
13.9
16.2
18.6
13.7
16.3
19.4
10 years
14.2
17.2
20.3
14.1
17.7
21.8
12 years
14.9
18.4
22.3
14.9
19.3
24.2
14 years
16.0
19.8
23.9
15.8
20.8
25.7
16 years
17.0
21.1
25.1
16.6
22.2
26.9
18 years
17.6
22.2
26.3
17.1
23.2
28.3
For parents seeking more in-depth information about child growth tracking, the CDC Childhood Obesity page at cdc.gov/obesity/childhood provides state-by-state prevalence data, information on evidence-based programs, and tools for parents. The Dietary Guidelines for Americans 2020-2025, published jointly by the USDA and HHS, include guidance on healthy eating patterns for children and adolescents at all weight status levels, emphasizing food quality and dietary variety rather than calorie restriction as the foundation of healthy childhood nutrition.
Child BMI Percentile Questions US Parents and Pediatricians Ask Most
Approximately 22 US states require or strongly recommend BMI screening in schools, where trained staff measure students’ height and weight, calculate BMI-for-age percentile, and in some states send the results home to parents in a report sometimes called a “BMI report card” or “FitnessGram.” School BMI screening programs vary significantly by state in terms of which grades are screened (commonly grades K, 2, 4, 6, 8, and 10), whether parents are notified, and whether results are shared with health departments. Proponents argue that school screening identifies children who might not be seen regularly by a pediatrician for follow-up. Critics raise concerns about stigma, privacy, and the limited clinical guidance provided alongside the numbers. If your child receives a BMI result from a school screening program, this calculator can help you understand the number, but the most important follow-up is always a conversation with your child’s pediatrician rather than relying solely on a school-generated report.
The CDC defines healthy weight for children ages 2 to 19 as a BMI-for-age between the 5th and 85th percentile for their age and sex. This means a healthy child can have any BMI percentile between 5 and 84.9. A percentile below 5 is classified as underweight, 85 to 94.9 is overweight, and 95 and above is obese. Note that the healthy percentile range spans an 80-percentile-point window (from the 5th to the 85th), so the large majority of healthy children fall within this range. A child at the 40th percentile and a child at the 75th percentile are both in the healthy weight category, even though they are at quite different points on the spectrum. The specific number within the healthy range is less important than whether the child is inside or outside the healthy range.
Children’s bodies change dramatically from age 2 to 19, with normal variations in body fat percentage, growth spurts, and puberty-related changes in lean mass and fat distribution affecting what a healthy BMI looks like at each age and sex. A BMI of 17 is in the healthy range for an 8-year-old but would be underweight for a 17-year-old. A BMI of 22 is overweight for a 9-year-old but healthy for a 17-year-old. Fixed adult BMI cutoffs would therefore significantly misclassify children’s weight status at many ages. The percentile approach solves this by comparing each child to same-age, same-sex peers, producing a consistent definition of healthy (5th to 85th percentile) that applies across all ages and both sexes without requiring different numerical BMI thresholds at each age.
The LMS method, developed by T.J. Cole and P.J. Green, is a statistical technique for constructing smooth growth reference curves that characterizes the distribution of measurements at each age using three parameters. L is the power in a Box-Cox transformation that corrects for the skewness (non-normality) of BMI distributions in children. M is the median (50th percentile) of BMI at each age and sex. S is the coefficient of variation (a measure of relative variability). From these three parameters, the Z-score for any BMI value is calculated as [(BMI/M)^L – 1]/(L*S), and the percentile is derived from the Z-score using the normal distribution. The CDC published LMS parameters for US children for every half-month of age from 2 to 20 years (Kuczmarski et al., 2002), and these are the parameters that underlie all legitimate pediatric BMI-for-age calculators. This calculator uses these LMS parameters at yearly intervals with interpolation for monthly age precision.
The first step is always to share the result with your child’s pediatrician, who can verify the measurement, review the child’s growth history, and assess whether the percentile represents a change in trend or a longstanding pattern. The 2023 American Academy of Pediatrics Clinical Practice Guideline on Pediatric Obesity recommends intensive health behavior and lifestyle treatment (IHBLT) as the first-line intervention for children with obesity, delivered by a multidisciplinary team that may include a pediatrician, registered dietitian, and behavioral health specialist. For children with overweight BMI (85th to 95th percentile), the same guideline recommends motivational interviewing and family-based behavior change support rather than restrictive dieting. Weight-loss medications are only approved for adolescents 12 and older with obesity. US parents should avoid placing children on restrictive calorie-limited diets without medical supervision, as this approach is associated with nutritional deficiency and disordered eating risk in the research literature. Focus conversations with children on healthy habits and feeling good rather than on weight or body appearance.
The CDC uses two separate sets of growth charts for US children. For infants and toddlers from birth to 24 months, the CDC recommends using the WHO growth standards (2006), which are based on a international sample of children raised under optimal conditions (breastfed, non-smoking households, regular healthcare). For children 2 years and older, the CDC uses the CDC 2000 Growth Charts, which are based on a nationally representative US reference sample. This calculator uses CDC 2000 Growth Charts for ages 2 to 19, consistent with clinical practice guidelines for US pediatric primary care. For children under 2, the Toddler BMI Calculator on this hub uses the WHO growth standards. The two chart systems use different reference populations and slightly different BMI distributions, which is why the calculator on this page does not accept ages below 2 years.
A BMI Z-score expresses a child’s BMI as the number of standard deviations above or below the median BMI for children of the same age and sex in the CDC reference population. A Z-score of 0 means the child is at exactly the 50th percentile. A Z-score of 1.0 corresponds to approximately the 84th percentile; a Z-score of 2.0 corresponds to approximately the 97.7th percentile; a Z-score of -1.0 corresponds to approximately the 16th percentile. US researchers and pediatric specialists often prefer Z-scores over percentiles when tracking children above the 97th percentile or below the 3rd percentile, because percentiles compress at the extremes (the difference between the 97th and 99th percentile is clinically significant but looks small on a 0-100 scale). Z-scores are also used in epidemiological research comparing child weight status across populations. This calculator shows the Z-score alongside the percentile and BMI in the results.
Puberty causes substantial changes in body composition that affect BMI independent of overall weight gain. In girls, puberty is associated with increases in body fat percentage, particularly in the hips, thighs, and breast tissue, which can raise BMI even if the girl is growing normally and eating appropriately for her development stage. In boys, puberty is associated with increases in lean muscle mass and bone density that also raise BMI. The CDC growth charts account for these expected puberty-related changes by using sex-specific and age-specific reference data that reflect average US children progressing through puberty at typical timelines. However, early or late puberty can cause temporary shifts in BMI percentile that a single calculator reading may misinterpret: a girl beginning puberty at age 9 may show a rising BMI percentile that reflects normal early development rather than problematic weight gain. Pediatricians factor pubertal stage (Tanner staging) into their interpretation of BMI-for-age trends in children and adolescents.
An online calculator that correctly implements the CDC LMS method (as this one does) produces BMI percentile results that are mathematically equivalent to those produced by clinical pediatric software, within the precision of the height and weight inputs provided. The main sources of inaccuracy in online child BMI calculations are input errors (imprecise home measurements of height and weight) rather than calculation errors. A 0.5-inch measurement error in a child’s height or a 1-pound error in weight can shift the percentile result by 1 to 5 percentile points, depending on where the child falls on the growth curve. Calculators that use simplified lookup tables rather than the LMS calculation method may produce results that differ by 2 to 8 percentile points from the exact LMS result, particularly for children near the category boundaries. This calculator uses full LMS computation rather than table lookup, so the mathematical result is as accurate as the measurements entered.
The CDC 2000 Growth Charts were developed by the National Center for Health Statistics (NCHS) and published in 2000 (Kuczmarski et al., 2000). They replaced the older 1977 NCHS growth charts and were designed to represent a broader, more racially and ethnically diverse US population. The 2000 charts were based on five major national surveys of US children’s measurements collected between 1963 and 1994, including the National Health and Nutrition Examination Surveys (NHANES I, II, and III) and the Hispanic Health and Nutrition Examination Survey (HHANES). The CDC BMI-for-age charts are one component of the 2000 Growth Chart set, which also includes length-for-age, weight-for-age, and weight-for-length charts for various age ranges. The CDC recommends using the 2000 BMI-for-age charts for all US children ages 2 to 19 in clinical practice. The complete growth chart set and LMS parameter files are available at no cost at cdc.gov/growthcharts.
From a CDC classification standpoint, any result at or above the 85th percentile (overweight) or at or above the 95th percentile (obese) warrants a conversation with your child’s pediatrician. Any result below the 5th percentile (underweight) also warrants pediatric follow-up. Within the healthy range, a single percentile value is rarely cause for concern. However, as noted by the American Academy of Pediatrics, trend matters more than a single reading: a child moving steadily upward in percentile (even within the healthy range) deserves attention and a discussion about healthy lifestyle habits at their next well-child visit. It is also worth noting that children of different ethnic and racial backgrounds may have different body composition at the same BMI percentile: US research suggests that Asian American children may carry more body fat at lower BMI percentiles than white children, similar to the observation for Asian American adults, though CDC category thresholds are not adjusted by race in routine US pediatric practice.
The US Preventive Services Task Force (USPSTF) recommends that clinicians screen for obesity in children ages 6 and older, and that children identified with obesity (BMI at or above the 95th percentile) be referred to or offered comprehensive intensive behavioral interventions. Under the Affordable Care Act, most US health insurance plans must cover this obesity screening and counseling without cost-sharing as a preventive service. In practice, pediatricians measure height and weight, calculate BMI-for-age percentile, and plot it on growth charts at every well-child preventive care visit. The AAP Bright Futures guidelines specify discussing BMI trends and healthy lifestyle habits at multiple well-child visit ages from age 2 onward. For children with overweight (85th to 95th percentile), the AAP recommends motivational interviewing and behavior change support within primary care. For children with obesity (95th percentile and above), the 2023 AAP guideline recommends referral to comprehensive multidisciplinary weight management programs that are available in many US children’s hospitals and pediatric specialty practices.
The standard CDC BMI-for-age percentile calculation used in this calculator was developed using a general US child population and may not be appropriate for children with certain medical conditions or disabilities. Children with Down syndrome, spina bifida, Prader-Willi syndrome, limb differences, or other conditions that significantly affect body composition or growth patterns may need condition-specific growth charts or individualized interpretation by a specialist pediatrician. The CDC has published condition-specific growth charts for Down syndrome (available at cdc.gov), and other specialty organizations have published reference data for specific pediatric conditions. Children who use wheelchairs or have mobility impairments may have different height measurement protocols and different healthy weight ranges than ambulatory children of the same age and sex. If your child has a medical condition that affects their growth or body composition, discuss BMI interpretation with their pediatric specialist rather than relying solely on the standard CDC growth chart thresholds.
The 95th percentile BMI varies by age and sex. Approximate values from the CDC 2000 Growth Charts: For boys, the 95th percentile BMI is approximately 17.0 at age 4, 18.5 at age 6, 20.3 at age 8, 22.5 at age 10, 24.9 at age 12, 26.8 at age 14, 28.3 at age 16, and 29.5 at age 18. For girls, the 95th percentile BMI is approximately 16.8 at age 4, 18.5 at age 6, 21.0 at age 8, 23.7 at age 10, 26.2 at age 12, 28.0 at age 14, 29.5 at age 16, and 31.0 at age 18. These values increase with age because normal BMI increases as children grow, and the 95th percentile threshold represents the upper 5% of the reference population at each age. A child whose BMI exceeds these values is classified as obese by CDC criteria. The calculator above provides the exact percentile for your child’s specific age, sex, height, and weight.
Yes, with some important caveats. The CDC 2000 Growth Charts used in this calculator were built from a US-born reference population and are designed for use in standard US pediatric practice regardless of the child’s country of origin. International pediatric guidelines from the WHO also recommend using the WHO or US CDC charts for children who have been adopted internationally and are growing up in the US, as these children’s growth patterns typically transition toward US reference norms over time. However, for children adopted from countries with high rates of early malnutrition or stunting, the catch-up growth pattern after adoption may produce rapid BMI percentile increases that look alarming but reflect normal nutritional recovery. Children adopted internationally may also have unknown birth dates, making age-for-BMI percentile calculations less precise. Pediatricians who specialize in international adoption medicine, available at major US children’s hospitals, are the best resource for interpreting growth data for internationally adopted children.
The CDC provides several free, authoritative resources for child BMI and growth monitoring. The CDC Healthy Schools BMI page at cdc.gov/healthyschools provides information on school-based BMI monitoring programs used in many US states. The CDC Growth Charts collection at cdc.gov/growthcharts includes printable clinical growth chart forms, training materials for healthcare providers, and the full LMS parameter data files used in this calculator. The CDC’s childhood obesity page at cdc.gov/obesity/childhood provides US prevalence data, state-by-state information, and links to evidence-based intervention programs. The American Academy of Pediatrics’ HealthyChildren.org website provides parent-friendly explanations of BMI-for-age, growth chart interpretation, and healthy lifestyle guidance for families. For children identified at clinical risk, the AAP’s national registry of comprehensive pediatric weight management programs (COMPASS) can help families find evidence-based clinical resources in their US region.
This child BMI percentile calculator uses the CDC LMS (Lambda-Mu-Sigma) method based on LMS parameters from Kuczmarski et al., 2002 (Advance Data from Vital and Health Statistics No. 314, National Center for Health Statistics). BMI-for-age category thresholds (underweight below 5th percentile, healthy weight 5th to 85th, overweight 85th to 95th, obese 95th and above) follow CDC clinical growth chart guidelines published at cdc.gov/growthcharts. The Abramowitz and Stegun normal CDF approximation (polynomial coefficients, 1964) is used for Z-score to percentile conversion. LMS values in this calculator use whole-year data with linear interpolation for monthly age precision. For children under 2 years, use the Toddler BMI Calculator (WHO growth standards). Results are estimates and may differ slightly from clinical tools using the full half-monthly LMS table.
BMI-for-age percentile is a screening tool only and must be interpreted by a qualified pediatric healthcare provider in the context of the child’s complete growth history and clinical presentation. This tool is not a substitute for pediatric medical evaluation. USCalculators.com has no affiliation with the CDC, AAP, NCHS, or any US government or medical body. Parents and caregivers should consult their child’s US pediatrician for all health assessments and treatment decisions. For authoritative pediatric growth information see CDC Growth Charts and HealthyChildren.org (AAP).