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Chinese National Weight-for-Stature Growth Chart (65-125 cm)

Plot a child's weight against Chinese National Standard reference data using standing height (stature) — not age — as the independent variable. The chart displays the standard percentile curves (3rd, 15th, 50th, 85th, 97th) for boys or girls and pins your child's point so you can see whether their weight is proportionate to their height on a China-specific reference.

LMS Method: Z = ((X/M)^L - 1) / (L × S), percentile = Φ(Z) × 100

How It Works

The Chinese National weight-for-stature chart answers a different question from weight-for-age: instead of asking "how does this child's weight compare to peers of the same age," it asks "how does this child's weight compare to peers of the same standing height on a China-specific reference?" The calculator looks up three parameters from the Chinese National weight-for-stature LMS table — L (skewness), M (the median weight at that stature), and S (coefficient of variation) — for the child's exact standing height in centimeters, regardless of age. It then computes a Z-score using the Box-Cox equation Z = ((X/M)^L − 1) / (L × S) and maps that Z-score through the standard normal CDF to a percentile. The Chinese table is indexed at 5-cm intervals from 65 cm to 125 cm, so intermediate statures are handled by linearly interpolating L, M, and S between the bracketing rows. Stature is measured with the child standing — the child is upright, heels together, looking forward — which typically reads about 0.7 cm shorter than recumbent length in the same child. The reference data come from large-scale Chinese national growth surveys and are the recommended standard for clinical use in mainland China for children measured standing up.

Example Problem

A boy with a standing height of 100 cm weighs 15.46 kg. Where does he fall on the Chinese National weight-for-stature chart?

  1. Select Boy for sex and confirm the weight and stature units (kg and cm in this example).
  2. Enter the standing height: 100.0 cm. Note that age is not used — only the measured stature matters.
  3. Enter the weight: 15.46 kg.
  4. Look up the Chinese National weight-for-stature LMS triple for boys at 100 cm: L ≈ -0.93, M ≈ 15.46 kg, S ≈ 0.0754.
  5. Compute the Z-score with Z = ((X/M)^L − 1) / (L × S). Substituting gives Z ≈ ((15.46/15.46)^-0.93 − 1) / (-0.93 × 0.0754) ≈ 0.00.
  6. Map the Z-score through the standard normal CDF: Φ(0.00) = 0.50, so the percentile is the 50th.
  7. Report the result: a boy 100 cm tall weighing 15.46 kg sits right at the Chinese median weight for his height.

Key Concepts

Weight-for-stature is a proportionality check, not an age check. A tall 4-year-old who is heavy for her age may be perfectly proportioned for her height; a short 4-year-old who looks average on weight-for-age may in fact be heavy-for-stature. The Chinese National standard treats weight-for-stature below the 3rd percentile (Z ≈ −2) as a wasting signal and above the 97th (Z ≈ +2) as overweight that warrants follow-up. The measurement used here is standing height (stature) — measured with the child upright against a stadiometer — not recumbent length. Recumbent length runs about 0.7 cm longer than standing height in the same child, so mixing the two can shift percentiles. The Chinese weight-for-stature chart covers statures from 65 cm to 125 cm (about 25.6 to 49.2 in); infants and toddlers who are measured lying down should be plotted on the Chinese weight-for-length chart instead.

Applications

  • Well-child visits in mainland China: pediatricians check weight-for-stature to confirm proportional growth alongside weight-for-age and stature-for-age on a China-specific reference.
  • Wasting screening in Chinese clinical settings: a weight-for-stature below the 3rd percentile is the primary screen for acute malnutrition on the Chinese standard once the child is measured standing.
  • Overweight surveillance in Chinese preschoolers and early school-age children: when weight-for-stature exceeds the 97th percentile, a nutritional conversation is typically initiated.
  • Population-specific proportionality screening when WHO or CDC charts over- or under-estimate normal Chinese body proportions.
  • Post-illness recovery in Chinese pediatric care — tracks whether a child has regained proportional weight after illness or hospitalization.
  • Overseas Chinese families and clinicians who want a China-specific percentile alongside the WHO or CDC value.

Common Mistakes

  • Confusing weight-for-stature with weight-for-age — they answer different questions; a child can be average on one and outside the normal range on the other.
  • Using recumbent length instead of standing height — lying-down measurements overstate the child's height by about 0.7 cm and shift the percentile upward. This chart is for children measured standing.
  • Entering stature in inches without switching the unit selector — verify the unit dropdown matches the measurement before typing.
  • Using this chart for a child whose stature is under 65 cm or over 125 cm — switch to a length-indexed chart (weight-for-length) for younger infants, or to weight-for-age / BMI for older children.
  • Treating a single high weight-for-stature percentile as a diagnosis — a solidly built child may always sit above the 85th without being unhealthy; trajectory matters more than a single point.
  • Mixing references across visits — once you start a child on the Chinese National weight-for-stature chart, stay on it rather than flipping between WHO, CDC, and Chinese values at each visit.

Frequently Asked Questions

What is the 50th percentile weight for a boy who is 100 cm tall on the Chinese chart?

On the Chinese National weight-for-stature chart, a 100 cm boy at the 50th percentile weighs approximately 15.46 kg (34.1 lb). A girl at the same stature at the 50th percentile weighs approximately 15.28 kg (33.7 lb). The 50th percentile is the Chinese median — half of same-sex children at that stature weigh more, half weigh less — it is not a goal weight every child is expected to hit.

How is weight-for-stature different from weight-for-age?

Weight-for-age compares the child's weight to peers of the same age; weight-for-stature compares weight to peers of the same standing height. A tall 4-year-old may be at the 90th on weight-for-age but only the 55th on weight-for-stature — perfectly proportioned, just larger. A short 4-year-old may be at the 40th on weight-for-age but the 90th on weight-for-stature — heavy for her body size even though her raw weight looks average. Pediatricians read both together, not in isolation.

Why does this calculator ignore age?

The Chinese National weight-for-stature table is indexed by stature only — the LMS parameters are looked up using the measured standing height in centimeters, not the child's age. This is deliberate: weight-for-stature is designed to assess body proportionality independently of age, which is exactly what's useful when you want to know whether a child's weight is in balance with their body size. If you need an age-based read, use the Chinese weight-for-age or stature-for-age calculators.

What stature range does this calculator cover?

The Chinese National weight-for-stature table covers standing heights from 65 cm to 125 cm (about 25.6 to 49.2 in) in 5-cm steps. Statures outside this range are not part of the Chinese weight-for-stature reference. For shorter children who are typically measured lying down, switch to the Chinese weight-for-length calculator. For older children outside this range, use weight-for-age or BMI-for-age on the Chinese standard.

Should I measure standing height or recumbent length?

This chart uses standing height (stature) — measured with the child upright against a stadiometer, heels together, looking forward. Recumbent length is typically about 0.7 cm longer than standing height in the same child, so using a lying-down measurement here will shift the percentile slightly upward. If your child is still being measured lying down, use the Chinese weight-for-length chart instead for a clean match between the measurement and the reference.

How does the Chinese National chart differ from WHO weight-for-stature?

The WHO weight-for-height chart is built from a multinational breastfed reference sample (WHO Multicentre Growth Reference Study, 2006) and describes how children should grow under optimal feeding and care conditions. The Chinese National chart is built from large-scale surveys of Chinese children and describes how Chinese children actually grow. Chinese children are, on average, slightly lighter for stature than the WHO median in the 2-5 year range, so the same weight may read near the Chinese 50th but below the WHO 50th. Either reference is defensible in the right setting — the Chinese chart is the clinical standard in mainland China.

How does weight-for-stature compare to weight-for-length, and when do children transition?

Both charts answer the same question — is weight proportionate to body size? — but they use different body-size measurements. Weight-for-length uses recumbent length for infants and young toddlers measured lying down; weight-for-stature uses standing height for children measured standing. Pediatricians typically switch from weight-for-length to weight-for-stature around the age when the child can stand still enough for an accurate stadiometer reading (usually around 24 months on the Chinese standard). Because standing height reads about 0.7 cm shorter than recumbent length in the same child, the two tables overlap at different percentile bands — stay on one chart until the transition visit so percentiles do not jump artificially.

What does "proportional growth" mean on a weight-for-stature chart?

Proportional growth means weight and stature are tracking along the same channel over time. A child at the 50th percentile for weight-for-stature on every visit is proportionally growing even if her raw weight keeps rising. A child who jumps from the 50th to the 90th on weight-for-stature (while her stature-for-age stays at the 50th) is gaining weight faster than height — the chart flags that imbalance. The single-point percentile answers "is weight proportionate to stature right now?" and the trend across visits answers "is growth staying proportional over time?"

Reference: Chinese National Standards for Growth and Development of Children. National Health Commission of the People's Republic of China. See also: Zong X-N, Li H. Construction of a new growth references for China based on urban Chinese children: comparison with the WHO growth standards. PLoS One. 2013;8(3):e59569.

Worked Examples

Healthy proportion check

A boy 100 cm tall weighing 15 kg — where does he fall on the Chinese chart?

A pediatrician in Shanghai is reviewing a healthy-term boy whose standing height is 100 cm and weight is 15 kg. The Chinese National weight-for-stature chart ignores age entirely — the LMS lookup is purely by stature.

  • Knowns: sex boy, stature 100.0 cm, weight 15.0 kg
  • Chinese LMS lookup at 100 cm (boys): L ≈ -0.93, M ≈ 15.46 kg, S ≈ 0.0754
  • Z = ((15.0 / 15.46)^-0.93 − 1) / (-0.93 × 0.0754) ≈ -0.41
  • Φ(-0.41) ≈ 0.34 → ~34th percentile
  • Result: ~34th percentile — slightly below the Chinese National median weight for his stature.

A single reading just under the median is reassuring; clinicians track whether the child continues along the same channel at subsequent visits.

US-units well-child visit

A girl 42 in tall weighing 40 lb — what Chinese percentile?

A parent reports their daughter's standing height as 42 in and weight as 40 lb. The calculator converts both to canonical units (42 in × 2.54 = 106.68 cm; 40 lb × 0.4536 = 18.14 kg) before the Chinese LMS lookup.

  • Knowns: sex girl, stature 42 in → 106.68 cm, weight 40 lb → 18.14 kg
  • Chinese LMS lookup at 106.68 cm (girls): L, M, S linearly interpolated between the 105 cm and 110 cm rows
  • Z ≈ ((18.14 / M)^L − 1) / (L × S) ≈ 1.14
  • Φ(1.14) ≈ 0.87 → ~87th percentile
  • Result: ~87th percentile — above the Chinese median for her stature, approaching the overweight band.

Chart values are for standing height — a recumbent measurement would read about 0.7 cm longer and shift the percentile slightly.

Wasting screen

A boy 115 cm tall weighing 16 kg — is there a wasting concern?

A preschooler presents at a follow-up visit measuring 115 cm tall and 16 kg. Weight-for-stature below the 3rd percentile is the primary acute-malnutrition screen on the Chinese National standard once a child is measured standing.

  • Knowns: sex boy, stature 115.0 cm, weight 16.0 kg
  • Chinese LMS lookup at 115 cm (boys): L ≈ -1.21, M ≈ 20.28 kg, S ≈ 0.089
  • Z ≈ ((16.0 / 20.28)^-1.21 − 1) / (-1.21 × 0.089) ≈ -2.68
  • Φ(-2.68) ≈ 0.004 → below the 1st percentile
  • Result: below the 1st percentile — past the −2 Z-score threshold flagged as wasting.

A single low reading warrants clinical assessment — nutrition history, illness, and growth trajectory together determine whether intervention is needed.

How the percentile is calculated

The calculator turns one pair of measurements — standing height and weight — into a percentile in three stages. First, it looks up three Chinese National parameters — L, M, and S — from the Chinese weight-for-stature reference table at the child's stature in centimeters. Age is not used — the independent variable on this chart is stature, not time. L is the Box-Cox power transform that accounts for skew in the weight distribution at that stature, M is the median weight of same-sex Chinese children at that stature, and S is the coefficient of variation. Second, it plugs those parameters into the Z-score formula:

Z score equals the quantity X divided by M, raised to the power L, minus 1, divided by L times S.

Where:

  • X — the child's measured weight in kilograms.
  • M — the Chinese median weight at that stature and sex.
  • L — the Box-Cox skewness parameter at that stature.
  • S — the coefficient of variation at that stature.

Third, the Z-score is mapped to a percentile through the standard normal cumulative distribution function, Φ(Z). A Z of 0 maps to the 50th percentile, −1.88 to the 3rd, and +1.88 to the 97th. The Chinese National weight-for-stature table is published at 5-cm steps from 65 cm to 125 cm, so fractional statures are handled by linearly interpolating L, M, and S between the two bracketing rows. Stature is the only input to the lookup — a child whose height falls in this range can be looked up at any age, though most Chinese clinicians reserve this chart for children who are routinely measured standing (typically from about 24 months onward).

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