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Child Growth Lab

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

CDC growth charts · Ages 2–19

Child Growth Chart Calculator

Enter birth and measurement dates, choose a CDC sex chart, and add standing height (without shoes), weight, or both. Each available measurement gets a percentile and reference view on the CDC height and weight charts for ages 2–19.

Free · no account · calculations run in the browser · measurements are not saved as child health records

Step 1 · Child details

Enter your child's details

Use the actual birth date and measurement date, then choose the CDC boys or girls chart.

CDC provides separate growth charts for boys and girls. Choose the chart used in your child's medical records.

Changing units clears measurement fields.

Step 2 · Measurements

Enter the measurements you have

Enter height, weight, or both. BMI is calculated only when both are entered.

Only have one measurement? This same record form accepts height alone or weight alone and returns only the supported result.

Measurement guidance

Confirm the exact dates and selected units. Measure standing height without shoes and use a digital scale on a firm, level surface for weight.

Height and weight can be entered separately; BMI needs both. Recumbent length cannot be entered as standing height.

For a child under 2, use the WHO Baby Growth Calculator.

How to measure standing height and weight

Results are age- and sex-specific reference comparisons for one measurement date, not diagnoses or growth trends. Have a child under 2? Use the WHO Baby Growth Calculator.

What this Child Growth Chart Calculator shows

All three are age- and sex-specific CDC comparisons, but they do not measure the same thing. Use this comparison to choose the result and follow-up resource that match your question.

Height-for-age

Inputs used: Standing height, exact age, and the selected sex chart.

Question answered: Where does the child’s current stature fall in the CDC reference?

What it does not answer: It does not describe weight status or predict adult height.

Best next resource: Understand height percentile

Weight-for-age

Inputs used: Weight, exact age, and the selected sex chart.

Question answered: Where does the child’s current body weight fall in the CDC reference?

What it does not answer: It does not adjust for height or classify weight status.

Best next resource: Understand weight percentile

BMI-for-age

Inputs used: Standing height, weight, exact age, and the selected sex chart.

Question answered: Where does BMI fall in the CDC reference, and which screening category applies?

What it does not answer: It does not diagnose a condition or directly measure body fat.

Best next resource: Understand BMI percentile

Working from a printed chart? Review how to follow CDC chart axes and percentile curves.

Worked example

A boy born 2007-10-01 and measured 2011-11-15 is 1,506 days old: 4 years, 1 month, and 14 days. At 105.4 cm and 16.9 kg, height is about the 71st percentile, weight is about the 58th percentile, and BMI is 15.2 with a BMI-for-age percentile of 35.9. The CDC screening category is Healthy weight range.

The percentiles differ because stature, body weight, and BMI answer different questions. The numbers do not contradict one another, and this single dated result cannot establish a growth trend.

Why three percentiles can be different

Height-for-age uses height, weight-for-age uses weight, and BMI-for-age relates weight to height. Each value is located in a different reference distribution, so the percentile numbers do not need to match. Different results do not mean the calculations conflict.

In the worked example above, the height percentile is higher than the weight percentile, while the BMI percentile is lower than both. That pattern simply reflects three different comparisons; this page does not infer a diagnosis, body type, or nutrition status from the combination.

How to measure standing height and weight

Measure standing height without shoes and use a digital scale on a firm, level surface for weight. Confirm the dates and units, and do not substitute recumbent length for standing height. See measurement technique and common mistakes.

Birth to before age 2

WHO baby growth standards

Use dated infant weight, recumbent length, and head-circumference records.

2nd birthday

Age 2 through 19

CDC child growth references

Use dated standing height and weight records; both together also support BMI-for-age.

Coming from an under-2 WHO chart?

The second-birthday handoff changes the reference, the measurement method, and the weight-status indicator. Read CDC vs WHO Growth Charts: Which One Should You Use? to understand why a percentile may shift and which calculator matches the record.

The age-2 handoff

In U.S. clinical settings, CDC recommends WHO growth standards from birth to age 2 and CDC growth charts beginning at age 2. The measurement also changes from recumbent length while lying down to standing height. A percentile may therefore change when both the chart and measurement method change; that change does not automatically represent a true growth problem. This site does not convert lying length to standing height.

If a result surprises you

  1. Confirm the birth and measurement dates.
  2. Confirm the selected units.
  3. Confirm that height and weight were entered in the correct fields.
  4. Repeat the measurement with consistent technique.
  5. Compare with previous dated records when available.
  6. Discuss a persistent concern with an appropriate healthcare professional.

How the calculations work

Exact elapsed age selects the CDC reference for the chosen sex chart. Standing height and weight use the CDC 2000 stature-for-age and weight-for-age LMS references. When both measurements are present, BMI is compared with the CDC BMI-for-age reference. BMI values at or below P95 use the CDC 2000 LMS calculation; only values above P95 use the 2022 Extended BMI calculation. That formula boundary is distinct from CDC guidance about using the plotted Extended growth charts for very high BMI above the 97th percentile. Formula details and source files are documented in the Methodology.

Limitations

  • Results are reference comparisons, not diagnoses.
  • One measurement does not establish a growth trend.
  • Measurement technique and data-entry accuracy affect the result.
  • The page does not predict adult height.
  • It does not automatically select a clinical chart for an individual child.
  • It does not recommend treatment.

Helpful context

Frequently asked questions

Can I enter only height or only weight?

Yes. Height alone produces a height-for-age percentile, and weight alone produces a weight-for-age percentile. BMI-for-age is calculated only when both height and weight are entered.

Why are height, weight, and BMI percentiles different?

They use different inputs and answer different questions. Each percentile is a position in its own age- and sex-specific reference distribution, so the three numbers do not need to match.

Is weight percentile the same as BMI percentile?

No. Weight-for-age does not account for height and is not a weight-status category. BMI relates weight to height and is then compared by age and sex.

Can one result show a growth trend?

No. This page reviews measurements from one date. A trend or growth-velocity calculation requires at least two accurate measurements with dates.

How do I use the Child Growth Chart Calculator?

Enter the birth date and measurement date, choose the CDC boys or girls chart, and enter standing height, weight, or both. Each measurement gives its age-based percentile; both together also give BMI, BMI-for-age percentile, and a screening category.

What age is this calculator for?

It is for children from the second birthday through age 19, ending the day before the 20th birthday.

What should I use for a child under 2?

Use the WHO Baby Growth Calculator from birth through the day before the second birthday. It uses recumbent length rather than standing height.

Does a percentile diagnose a health problem?

No. Height, weight, and BMI percentiles are reference comparisons. Growth charts and BMI screening categories are not intended to diagnose a condition by themselves.

Does this site save my child’s measurements?

No. Calculator inputs are processed in your browser and are not saved as a child health record or sent to an external calculation service.

Understand this result

How to Read a CDC Growth Chart

Understand CDC height-for-age and weight-for-age results, chart axes, measurement quality, and repeated patterns.