Child and Teen BMI Percentile Calculator

Updated Oct 2026 Used 2 times

Your result

BMI-for-age percentile

Enter your values, then calculate to see a verified result.

Inputs usedReview the information used for this result.

Full calculation and sourcesOpen Full calculation and sources to review the method, assumptions, boundaries, and evidence.

Versioned calculationFormula v1.0.0

What is calculated

CDC BMI-for-age percentile from exact LMS values for completed months 24-239.

Method

Calculate BMI, look up L/M/S, calculate z-score, then convert z to percentile.

Important boundary

A single percentile cannot assess growth pattern, body composition, or health.

Enter exact age and measurementsUse the labeled field and matching unit.

Apply CDC LMS dataThe calculator applies the displayed method at full precision.

Interpret with growth historyKeep the stated boundary beside the result.

Interpretation

The percentile compares BMI with the selected CDC age/sex reference.

BMI and z-score remain visible for reproducibility.

Use pediatric clinical guidance for diagnosis or treatment.

Use this result

WHO Child Growth Percentile CalculatorUse the WHO birth-to-five weight, stature and head-circumference standards.Adult BMI CalculatorUse adult categories only when age-appropriate.Body Fat CalculatorKeep body-composition estimation separate from BMI-for-age screening.

Keep exploring

4 related pages

Method and test recordFormula v1.0.0

Recorded scope: health-evidence-completion
Publisher: CalculatorGeek
Recorded review date: 2026-10-05
Next source review: 2027-04-05
Definition fixtures: 2 configured scenarios
Published examples: 2 shown below

Recorded method

Verify the CDC mirror checksum, table row mapping for months 24-239, LMS equation, normal CDF, metric/imperial parity, and category boundaries.

These records describe the published model and reference tests. A test-case count is not a certification of every possible input or an independent specialist review. Editorial policy

Known limitations

CDC reference population and sex-specific tables may not answer every clinical question.
Measurement error and exact age matter.
BMI does not directly measure body fat.
Children under 2 and adults are outside this route.

Method sources

Latest model update

2026-10-10 - Completed missing semantic entities, relationships, answer targets, query themes, questions, and visible input/output meaning without changing the calculation model.

Reference inputs and expected results

Up to 12 examples from the configured definition fixtures are shown. Expected values use the stated output units; invalid inputs are intended to be rejected.

Case	Inputs	Expected result
male CDC median at 24 months	CDC growth-chart sex table: male; Completed years: 2 years; Additional completed months: 0 months; Height: 1 m; Weight: 16.57502768 kg	Age used by the table: 24 months; BMI: 16.57502768 kg/m2; CDC LMS z-score: 0; BMI-for-age percentile: 50.00000005 %; classification: healthy-weight (allowed numeric tolerance: 0.001)
female CDC median at 24 months	CDC growth-chart sex table: female; Completed years: 2 years; Additional completed months: 0 months; Height: 1 m; Weight: 16.42339664 kg	CDC LMS z-score: 0; BMI-for-age percentile: 50.00000005 % (allowed numeric tolerance: 0.001)

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On this page

What the Child and Teen BMI Percentile Calculator calculates

Calculate BMI-for-age percentile for ages 2-19 using the CDC LMS data table and exact completed month of age.

This is a distinct pediatric reference workflow and does not reuse adult BMI categories.

Start with the Health calculators hub when a neighboring workflow better matches the question.

For children from birth through five years, compare weight, stature and head circumference with the WHO Child Growth Percentile Calculator; this CDC BMI route remains a separate age-two-through-19 screening workflow.

How to use the Child and Teen BMI Percentile Calculator

Select the CDC sex-specific table.
Enter completed years and additional months.
Enter same-date measured height and weight.
Review percentile with longitudinal growth and a qualified pediatric professional.

Continue with the Adult BMI Calculator. Use adult categories only when age-appropriate.

Formula, variables and calculation order

BMI = kg / m^2; then use the CDC age/sex L, M, and S values in the LMS z-score equation and standard normal cumulative distribution.

Inputs are validated and normalized before the calculation. Working precision is retained until display rounding.

For a separate body-composition estimate, open the Body Fat Calculator. Keep that adult estimate separate from BMI-for-age screening.

Worked example and boundary check

Worked example

At the CDC median BMI M for a given sex and month, z equals 0 and the percentile is about 50.

Boundary check

The route accepts completed months 24 through 239; adult BMI categories are not substituted.

How to interpret the result

The CDC categories describe a screening percentile, not body-fat percentage or a standalone diagnosis.

CDC reference population and sex-specific tables may not answer every clinical question.
Measurement error and exact age matter.
BMI does not directly measure body fat.
Children under 2 and adults are outside this route.

Use the Height Calculator when a measured height needs unit conversion before an age-appropriate calculation.

Inputs, outputs and result meaning

Uses exact completed-month CDC LMS data rather than approximating with adult categories or broad age bands.

Inputs

CDC growth-chart sex table: Select the CDC LMS table used for the calculation. Available choices are Male table and Female table.
Completed years: The CDC BMI-for-age data cover ages 2 through 19 years. Supported units are years.
Additional completed months: Enter 0 through 11 additional months. Supported units are months.
Height: Use a measured standing height. Supported units are meters (m), centimeters (cm), and inches (in).
Weight: Use a measured weight from the same date. Supported units are kilograms (kg) and pounds (lb).

Outputs

BMI-for-age percentile: This is the primary result. It is displayed in %. The display rule uses up to 1 decimal places.
BMI: It is displayed in kg/m2. The display rule uses up to 1 decimal places.
CDC LMS z-score: The display rule uses up to 3 decimal places.
Age used by the table: It is displayed in months. The display rule uses up to 0 decimal places.

BMI = weight / height squared; CDC LMS z = ((BMI/M)^L - 1)/(L x S); percentile = standard normal CDF(z) x 100. Keep the result label, unit, selected mode, and stated limitations together when sharing the answer.

Frequently asked questions

Why enter months?

The CDC LMS values change by completed month.

Is the 50th percentile an ideal target?

No; growth pattern and context matter.

Can I use adult BMI cutoffs?

No.

Does percentile diagnose obesity-related disease?

No.

Primary sources and evidence limits

Sources and version-sensitive boundaries were checked 2026-10-05. The page does not replace diagnosis, prescribing, emergency care, or individualized professional judgment.