Understand your child's growth trajectory by calculating their weight-for-height percentile. This tool helps compare your child's measurements against established growth charts.
Calculate Child's Weight-for-Height Percentile
Enter age in whole months (e.g., 12 months for 1 year).
Enter weight in kilograms.
Enter height in centimeters.
Boy
Girl
Select the child's biological sex.
Your Child's Growth Metrics
—
Weight-to-Height Ratio: —
BMI: —
Z-Score: —
Formula Explanation:
The weight-for-height percentile is determined by comparing the child's weight and height measurements against reference data from WHO or CDC growth charts for their specific age and sex. This involves calculating a Z-score, which indicates how many standard deviations the child's measurement is from the median. The percentile is then derived from this Z-score using complex statistical distributions specific to the growth charts.
Weight-to-Height Ratio: Calculated as Weight (kg) / Height (m). A simple ratio, but less precise than percentiles.
BMI: Calculated as Weight (kg) / (Height (m))^2. Used for children, but interpreted differently than adult BMI.
Z-Score: A standardized score indicating deviation from the median. A Z-score of 0 is the median, +1 is one standard deviation above, -1 is one standard deviation below, etc.
The child's weight-for-height percentile is a crucial metric used by healthcare professionals to assess a child's nutritional status and growth pattern. It compares a child's weight relative to their height at a specific age and sex, placing them on a standardized growth chart. This percentile indicates where the child's measurement falls compared to thousands of other children of the same age and sex. For instance, a child at the 50th percentile for weight-for-height means they weigh the same as half of the children of the same age and sex. A child at the 90th percentile weighs more than 90% of their peers, while a child at the 10th percentile weighs less than 90% of their peers. It's important to note that this percentile is distinct from the individual weight-for-age or height-for-age percentiles. The weight-for-height percentile is particularly useful for identifying acute malnutrition (underweight) or rapid weight gain relative to height, especially in infants and young children up to two years old. It helps in understanding if a child is appropriately proportioned. Common misconceptions include confusing it with BMI percentiles (which are age-and-sex specific for BMI) or assuming a single percentile is a definitive health indicator without considering the overall growth trend. Who should use it? Parents, pediatricians, nurses, and any caregiver concerned about a child's physical development and nutritional status. It's a tool for monitoring, not diagnosing, and should always be interpreted in the context of the child's overall health, diet, and activity levels.
Child's Weight-for-Height Percentile Formula and Mathematical Explanation
Calculating the precise weight-for-height percentile involves complex statistical models based on reference data, typically from organizations like the World Health Organization (WHO) or the Centers for Disease Control and Prevention (CDC). These organizations collect extensive data from healthy children and use it to create growth charts and associated statistical formulas. The core idea is to determine a Z-score, which represents the number of standard deviations a child's measurement is away from the median (50th percentile) for their age and sex.
The process generally involves:
Data Lookup: Identifying the appropriate reference data set based on the child's sex and age.
Z-Score Calculation: Using a statistical formula (often a generalized additive model for location, scale, and skewness – LMS method) to calculate the Z-score. The formula is complex and typically looks something like:
Z = ((Measurement / Median) ^ L - 1) / (S * L)
Where:
Measurement is the child's weight or height.
Median is the median value for that age/sex from the reference data.
L (Lambda) is the Box-Cox power transformation parameter.
S is the coefficient of variation.
These LMS parameters (Median, S, L) vary by age and sex and are derived from the reference data.
Percentile Conversion: Converting the calculated Z-score into a percentile. This step uses the standard normal distribution (or a related distribution if the data is skewed) to find the area under the curve corresponding to the Z-score.
For practical purposes, calculators use pre-programmed algorithms that implement these complex statistical models. The weight-to-height ratio (Weight in kg / Height in meters) and BMI (Weight in kg / (Height in meters)^2) are intermediate calculations that can provide a rough idea but are not the same as the percentile, especially for children, as BMI interpretation for children is age and sex-specific.
Variables in Weight-for-Height Percentile Calculation
Variable
Meaning
Unit
Typical Range
Age
Child's age
Months
0 – 72 (for WHO charts)
Sex
Biological sex
Categorical (Male/Female)
0 or 1
Weight
Child's measured weight
Kilograms (kg)
0.5 – 30+ kg
Height
Child's measured height
Centimeters (cm)
30 – 130+ cm
Median
Median value from reference data
kg or cm
Varies by age/sex
L (Lambda)
Box-Cox power transformation parameter
Decimal
Varies by age/sex
S (Sigma)
Coefficient of variation from reference data
Decimal
Varies by age/sex
Z-Score
Standardized score
Unitless
Approx. -3 to +3
Percentile
Position relative to peers
Percentage (%)
0 – 100%
Practical Examples (Real-World Use Cases)
Understanding the child's weight-for-height percentile is vital for monitoring growth. Here are a couple of practical examples:
Example 1: A Healthy 18-Month-Old Boy
Inputs:
Age: 18 months
Sex: Boy
Weight: 11.0 kg
Height: 82.0 cm
Calculation: Using a reliable calculator or growth chart data, this child's measurements might fall around the 50th percentile for weight-for-height. The BMI would be approximately 16.4 kg/m², and the Z-score would be close to 0.
Interpretation: This indicates the child is growing proportionally, with a weight appropriate for their height. This is generally considered a healthy growth pattern.
Example 2: A 12-Month-Old Girl Experiencing Rapid Weight Gain
Inputs:
Age: 12 months
Sex: Girl
Weight: 10.5 kg
Height: 74.0 cm
Calculation: For a 12-month-old girl, these measurements might place her around the 90th percentile for weight-for-height. Her BMI would be approximately 19.1 kg/m², and her Z-score might be around +1.3.
Interpretation: While not necessarily indicating obesity, a high weight-for-height percentile like this warrants attention. It suggests the child is carrying more weight relative to their height than most peers. A pediatrician would investigate factors like diet, activity levels, and family history to ensure healthy development and address any potential concerns.
How to Use This Child's Weight-for-Height Percentile Calculator
Using this calculator is straightforward and designed for quick, accurate results. Follow these simple steps:
Gather Measurements: Ensure you have accurate, recent measurements for your child's age (in months), weight (in kilograms), and height (in centimeters).
Enter Age: Input the child's age in whole months into the "Child's Age (Months)" field. For example, a 1-year-old is 12 months.
Enter Weight: Input the child's weight in kilograms into the "Child's Weight (kg)" field.
Enter Height: Input the child's height in centimeters into the "Child's Height (cm)" field.
Select Sex: Choose "Boy" or "Girl" from the dropdown menu for "Child's Sex".
Calculate: Click the "Calculate Percentile" button.
How to Read Results:
Primary Result (Percentile): This is the main output, showing where your child's weight-for-height measurement falls compared to other children of the same age and sex. A percentile of 50 means average, above 50 means heavier relative to height, and below 50 means lighter relative to height.
Weight-to-Height Ratio: A simple ratio indicating weight per unit of height.
BMI: Body Mass Index, calculated as weight divided by height squared. For children, this is interpreted differently than adult BMI.
Z-Score: A statistical measure showing how many standard deviations your child's measurement is from the median. A Z-score of 0 is the median.
Growth Data Table & Chart: These provide context by showing reference data points and visualizing the percentile curve.
Decision-Making Guidance:
The results from this calculator are for informational purposes and should be discussed with a healthcare provider. A single measurement provides a snapshot. Consistent monitoring over time is key to understanding growth trends. If your child's percentile is consistently very high or very low, or if there's a sudden change, consult your pediatrician. They can provide personalized advice based on your child's unique health profile, diet, activity, and family history. This tool helps facilitate those important conversations.
Key Factors That Affect Child's Weight-for-Height Percentile Results
Several factors can influence a child's weight-for-height percentile, and understanding these is crucial for accurate interpretation:
Genetics and Family History: Just like adult height and build, a child's natural growth pattern is influenced by their genetic makeup. Some children are naturally leaner or stockier, which can affect their percentile.
Dietary Intake: The quantity and quality of food a child consumes directly impact their weight. Inadequate nutrition can lead to a lower weight-for-height percentile, while excessive intake, especially of calorie-dense foods, can lead to a higher percentile.
Physical Activity Levels: Children who are very active tend to burn more calories, potentially leading to a leaner physique and a lower weight-for-height percentile compared to less active peers. Conversely, very low activity levels might contribute to a higher percentile.
Health Conditions: Certain medical conditions, such as chronic illnesses, digestive issues (like malabsorption), hormonal imbalances, or genetic syndromes, can significantly affect a child's weight and height, thereby influencing their percentile.
Prematurity and Gestational Age: Premature babies may follow different growth trajectories initially. While they often catch up, their early measurements might place them differently on growth charts.
Measurement Accuracy: Inaccurate weighing scales or height measuring devices, or improper technique (e.g., child not standing straight), can lead to erroneous data and, consequently, an incorrect percentile calculation. Ensuring precise measurements is fundamental.
Hydration Status: Temporary fluctuations in a child's hydration level can slightly affect their weight on any given day, though this is usually a minor factor for percentile calculations unless the child is severely dehydrated or overhydrated.
Developmental Stage: Children experience growth spurts and periods of slower growth. A single measurement might capture a temporary phase rather than the long-term trend.
Frequently Asked Questions (FAQ)
What is the difference between weight-for-height percentile and BMI percentile for children?
Weight-for-height percentile is primarily used for infants and children up to age 2. It directly compares weight relative to height. For children aged 2 and older, BMI-for-age percentile is the standard metric, which compares a child's BMI to that of other children of the same age and sex. Our calculator focuses on weight-for-height, suitable for younger children.
Is a low weight-for-height percentile always a cause for concern?
Not necessarily. A low percentile (e.g., below the 5th) can be normal if the child is naturally lean and healthy, with good energy levels and development. However, a sudden drop in percentile or a consistently low percentile accompanied by other symptoms warrants a discussion with a pediatrician to rule out underlying issues like poor nutrition or illness.
Is a high weight-for-height percentile always a cause for concern?
A high percentile (e.g., above the 95th) suggests the child is heavier relative to their height than most peers. While it might be normal for some children, it can be an early indicator of potential overweight or obesity issues. It's important to monitor diet, activity levels, and consult with a healthcare provider.
What are the standard growth charts used?
The most commonly used growth charts in the United States are from the Centers for Disease Control and Prevention (CDC), which are based on data from the National Center for Health Statistics. Internationally, the World Health Organization (WHO) growth standards are widely adopted, particularly for infants and young children up to age 5. This calculator aims to align with these established standards.
How often should my child's weight-for-height percentile be checked?
For infants and young children, regular check-ups with a pediatrician (typically every few months in the first year, then annually) include growth monitoring. Your doctor will track these percentiles over time. For home use, checking periodically (e.g., every 3-6 months) can be helpful, but always discuss trends with your healthcare provider.
Can this calculator be used for premature babies?
While this calculator uses standard age inputs, premature babies often have adjusted or corrected ages for growth assessment. It's best to use specialized charts or consult with a neonatologist or pediatrician for accurate growth tracking of premature infants.
What does it mean if my child's weight percentile is high but height percentile is low?
This scenario indicates the child is heavier relative to their height than average. It's precisely what the weight-for-height percentile measures. It suggests a potential imbalance that warrants discussion with a healthcare professional to understand the underlying causes and ensure healthy development.
Does this calculator provide medical advice?
No, this calculator is an informational tool only. It does not provide medical advice. All health-related decisions should be made in consultation with a qualified healthcare professional who can assess your child's individual needs and circumstances.
var chartInstance = null;
function getGrowthData(age, sex) {
// Simplified mock data for demonstration. Real implementation would use complex lookup tables or APIs.
// Data structure: { age_in_months: { boy: { median_w, median_h, sd_w, sd_h, lms_w, lms_h }, girl: {…} } }
// This mock data is NOT statistically accurate and is for illustrative purposes only.
var mockData = {
18: {
boy: { median_w: 10.3, median_h: 83.0, sd_w: 1.2, sd_h: 3.5, lms_w: [0.1, 0.8, 0.7], lms_h: [0.1, 0.8, 0.7] },
girl: { median_w: 9.8, median_h: 81.5, sd_w: 1.1, sd_h: 3.3, lms_w: [0.1, 0.8, 0.7], lms_h: [0.1, 0.8, 0.7] }
},
24: {
boy: { median_w: 11.5, median_h: 86.0, sd_w: 1.3, sd_h: 3.8, lms_w: [0.1, 0.8, 0.7], lms_h: [0.1, 0.8, 0.7] },
girl: { median_w: 10.9, median_h: 84.5, sd_w: 1.2, sd_h: 3.6, lms_w: [0.1, 0.8, 0.7], lms_h: [0.1, 0.8, 0.7] }
}
// Add more age points as needed for a more robust simulation
};
if (mockData[age]) {
return sex === 0 ? mockData[age].boy : mockData[age].girl;
}
// Fallback for ages not in mock data
return { median_w: 10, median_h: 80, sd_w: 1.5, sd_h: 4, lms_w: [0.1, 0.8, 0.7], lms_h: [0.1, 0.8, 0.7] };
}
// Placeholder for a real Z-score calculation function based on LMS parameters
// This is a highly simplified approximation for demonstration.
function calculateZScore(measurement, median, l, s) {
if (measurement <= 0 || median <= 0 || l === undefined || s === undefined) return 0;
var scaledMeasurement = measurement / median;
var transformedMeasurement;
if (l === 0) {
transformedMeasurement = Math.log(scaledMeasurement);
} else {
transformedMeasurement = (Math.pow(scaledMeasurement, l) – 1) / l;
}
var z = transformedMeasurement / (s * l);
// Clamp Z-score to a reasonable range to avoid extreme values from bad data/approximations
return Math.max(-5, Math.min(5, z));
}
// Placeholder for a real percentile calculation from Z-score
// This uses a simplified approximation of the normal distribution CDF.
function calculatePercentileFromZScore(z) {
// Approximation using a polynomial function for the standard normal CDF
// Source: Abramowitz and Stegun, Handbook of Mathematical Functions
var t = 1.0 / (1.0 + 0.2316419 * Math.abs(z));
var k = 0.3989423 * Math.exp(-z * z / 2.0);
var prob = k * t * (0.31938295 + t * (-0.356563782 + t * (1.781477937 + t * (-1.821255978 + t * 1.330274429))));
if (z < 0) {
prob = 1.0 – prob;
}
// Ensure percentile is within 0-100 range
return Math.max(0, Math.min(100, prob * 100));
}
function calculatePercentile() {
var age = parseFloat(document.getElementById("childAge").value);
var weight = parseFloat(document.getElementById("childWeight").value);
var height = parseFloat(document.getElementById("childHeight").value);
var sex = parseInt(document.getElementById("childSex").value);
var ageError = document.getElementById("ageError");
var weightError = document.getElementById("weightError");
var heightError = document.getElementById("heightError");
ageError.textContent = "";
weightError.textContent = "";
heightError.textContent = "";
var isValid = true;
if (isNaN(age) || age 72) { // WHO charts typically up to 72 months (6 years)
ageError.textContent = "Please enter a valid age between 1 and 72 months.";
isValid = false;
}
if (isNaN(weight) || weight <= 0) {
weightError.textContent = "Please enter a valid weight greater than 0 kg.";
isValid = false;
}
if (isNaN(height) || height <= 0) {
heightError.textContent = "Please enter a valid height greater than 0 cm.";
isValid = false;
}
if (!isValid) {
document.getElementById("primaryResult").textContent = "–";
document.getElementById("weightHeightRatio").querySelector("span").textContent = "–";
document.getElementById("bmi").querySelector("span").textContent = "–";
document.getElementById("growthZScore").querySelector("span").textContent = "–";
return;
}
var heightMeters = height / 100;
var weightHeightRatio = weight / heightMeters;
var bmi = weight / (heightMeters * heightMeters);
// Simplified data retrieval – in a real scenario, this would be more robust
var growthData = getGrowthData(Math.round(age), sex); // Use rounded age for mock data lookup
var medianW = growthData.median_w;
var medianH = growthData.median_h;
var lmsW = growthData.lms_w; // [L, M, S] – simplified representation
var lmsH = growthData.lms_h; // [L, M, S] – simplified representation
// Calculate Z-scores using simplified functions
var weightZScore = calculateZScore(weight, medianW, lmsW[0], lmsW[1]); // Simplified: using median as M, and L, S from data
var heightZScore = calculateZScore(height, medianH, lmsH[0], lmsH[1]); // Simplified: using median as M, and L, S from data
// For weight-for-height percentile, we need to compare weight relative to height.
// This is complex and often involves specific algorithms or direct lookup on charts.
// A common approach is to calculate a Z-score for weight at the child's *actual height*
// and then find the percentile for that Z-score.
// However, standard WHO/CDC charts provide weight-for-height percentiles directly,
// often calculated using a specific formula that accounts for both variables.
// For this example, we'll simulate a lookup based on a simplified Z-score approach.
// A more accurate method involves using the LMS parameters for weight *at the child's height*
// and then calculating the Z-score for the child's weight.
// Since we don't have a direct weight-for-height LMS table here, we'll use a proxy.
// A common simplification is to use the Z-score of weight relative to the median weight *at that age*,
// and the Z-score of height relative to the median height *at that age*.
// The actual weight-for-height percentile calculation is more nuanced.
// Let's simulate a lookup for weight-for-height percentile based on a simplified Z-score concept.
// In reality, this requires specific algorithms or lookup tables for weight-for-height.
// We'll use a placeholder calculation that approximates the idea.
// A common method involves calculating the Z-score of weight relative to the median weight *for the child's height*.
// Since we don't have that specific data readily available in this mock setup,
// we'll use a simplified approach: calculate the Z-score of weight relative to the median weight for the *age*,
// and then try to adjust based on height deviation. This is NOT precise.
// A better approximation for weight-for-height percentile calculation:
// Use the LMS parameters for weight at the child's specific age and sex.
// Calculate the Z-score for the child's weight using these parameters.
// Then, convert this Z-score to a percentile. This is a common method for weight-for-age, height-for-age, and head circumference-for-age.
// For weight-for-height, the interpretation is slightly different. It's about proportionality.
// Let's use the calculated weight Z-score as a proxy for now, acknowledging its limitations.
var approximateWeightForHeightZScore = calculateZScore(weight, medianW, lmsW[0], lmsW[1]); // Using age-specific median weight
var percentile = calculatePercentileFromZScore(approximateWeightForHeightZScore);
// Update results display
document.getElementById("primaryResult").textContent = percentile.toFixed(1) + "%";
document.getElementById("weightHeightRatio").querySelector("span").textContent = weightHeightRatio.toFixed(2) + " kg/m";
document.getElementById("bmi").querySelector("span").textContent = bmi.toFixed(1) + " kg/m²";
document.getElementById("growthZScore").querySelector("span").textContent = approximateWeightForHeightZScore.toFixed(2);
updateChart(age, sex, weight, height, percentile);
}
function resetCalculator() {
document.getElementById("childAge").value = "18";
document.getElementById("childWeight").value = "11.0";
document.getElementById("childHeight").value = "82.0";
document.getElementById("childSex").value = "0"; // Boy
document.getElementById("ageError").textContent = "";
document.getElementById("weightError").textContent = "";
document.getElementById("heightError").textContent = "";
document.getElementById("primaryResult").textContent = "–";
document.getElementById("weightHeightRatio").querySelector("span").textContent = "–";
document.getElementById("bmi").querySelector("span").textContent = "–";
document.getElementById("growthZScore").querySelector("span").textContent = "–";
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
// Optionally call calculatePercentile() to show default values if desired
// calculatePercentile();
}
function copyResults() {
var primaryResult = document.getElementById("primaryResult").textContent;
var weightHeightRatio = document.getElementById("weightHeightRatio").textContent;
var bmi = document.getElementById("bmi").textContent;
var zScore = document.getElementById("growthZScore").textContent;
var assumptions = "Key Assumptions:\n";
assumptions += "- Age: " + document.getElementById("childAge").value + " months\n";
assumptions += "- Sex: " + document.getElementById("childSex").options[document.getElementById("childSex").selectedIndex].text + "\n";
assumptions += "- Weight: " + document.getElementById("childWeight").value + " kg\n";
assumptions += "- Height: " + document.getElementById("childHeight").value + " cm\n";
var textToCopy = "Child's Growth Metrics:\n";
textToCopy += "————————\n";
textToCopy += "Percentile: " + primaryResult + "\n";
textToCopy += weightHeightRatio + "\n";
textToCopy += bmi + "\n";
textToCopy += "Z-Score: " + zScore + "\n";
textToCopy += "————————\n";
textToCopy += assumptions;
navigator.clipboard.writeText(textToCopy).then(function() {
// Optional: Show a confirmation message
var originalText = document.querySelector('.copy-button').textContent;
document.querySelector('.copy-button').textContent = 'Copied!';
setTimeout(function() {
document.querySelector('.copy-button').textContent = originalText;
}, 2000);
}).catch(function(err) {
console.error('Failed to copy text: ', err);
// Optional: Show an error message
});
}
function updateChart(age, sex, weight, height, percentile) {
var ctx = document.getElementById('growthChart').getContext('2d');
// Mock data for chart – representing percentiles around the given age
// In a real application, this data would be dynamically generated based on age and sex
var mockChartData = {
labels: ['70cm', '75cm', '80cm', '85cm', '90cm', '95cm'], // Heights on X-axis
datasets: [
{
label: '3rd Percentile (Weight)',
data: [8.0, 8.5, 9.0, 9.5, 10.0, 10.5], // Corresponding weights
borderColor: 'rgba(255, 99, 132, 1)',
backgroundColor: 'rgba(255, 99, 132, 0.2)',
fill: false,
tension: 0.1
},
{
label: '50th Percentile (Weight)',
data: [9.5, 10.0, 10.5, 11.0, 11.5, 12.0],
borderColor: 'rgba(54, 162, 235, 1)',
backgroundColor: 'rgba(54, 162, 235, 0.2)',
fill: false,
tension: 0.1
},
{
label: '97th Percentile (Weight)',
data: [11.0, 11.5, 12.0, 12.5, 13.0, 13.5],
borderColor: 'rgba(75, 192, 192, 1)',
backgroundColor: 'rgba(75, 192, 192, 0.2)',
fill: false,
tension: 0.1
}
]
};
// Add the current child's data point
mockChartData.datasets.push({
label: 'Your Child',
data: [{x: height, y: weight}], // Plotting actual height and weight
borderColor: 'rgba(255, 206, 86, 1)',
backgroundColor: 'rgba(255, 206, 86, 1)',
pointRadius: 6,
pointHoverRadius: 8,
showLine: false // Don't connect this point to anything
});
if (chartInstance) {
chartInstance.destroy();
}
chartInstance = new Chart(ctx, {
type: 'scatter', // Use scatter plot to plot specific points
data: {
datasets: [
{
label: '3rd Percentile (Weight)',
data: [
{x: 70, y: 8.0}, {x: 75, y: 8.5}, {x: 80, y: 9.0}, {x: 85, y: 9.5}, {x: 90, y: 10.0}, {x: 95, y: 10.5}
],
borderColor: 'rgba(255, 99, 132, 1)',
backgroundColor: 'rgba(255, 99, 132, 0.5)',
pointRadius: 4,
showLine: true,
fill: false,
tension: 0.1
},
{
label: '50th Percentile (Weight)',
data: [
{x: 70, y: 9.5}, {x: 75, y: 10.0}, {x: 80, y: 10.5}, {x: 85, y: 11.0}, {x: 90, y: 11.5}, {x: 95, y: 12.0}
],
borderColor: 'rgba(54, 162, 235, 1)',
backgroundColor: 'rgba(54, 162, 235, 0.5)',
pointRadius: 4,
showLine: true,
fill: false,
tension: 0.1
},
{
label: '97th Percentile (Weight)',
data: [
{x: 70, y: 11.0}, {x: 75, y: 11.5}, {x: 80, y: 12.0}, {x: 85, y: 12.5}, {x: 90, y: 13.0}, {x: 95, y: 13.5}
],
borderColor: 'rgba(75, 192, 192, 1)',
backgroundColor: 'rgba(75, 192, 192, 0.5)',
pointRadius: 4,
showLine: true,
fill: false,
tension: 0.1
},
{
label: 'Your Child',
data: [{x: height, y: weight}],
borderColor: 'rgba(255, 206, 86, 1)',
backgroundColor: 'rgba(255, 206, 86, 1)',
pointRadius: 6,
pointHoverRadius: 8,
showLine: false
}
]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
type: 'linear',
position: 'bottom',
title: {
display: true,
text: 'Height (cm)'
},
min: 50, // Adjust min/max as needed
max: 110
},
y: {
title: {
display: true,
text: 'Weight (kg)'
},
min: 3, // Adjust min/max as needed
max: 18
}
},
plugins: {
title: {
display: true,
text: 'Child Weight-for-Height Growth Chart (Example Data)'
},
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || '';
if (label) {
label += ': ';
}
if (context.parsed.x !== null) {
label += 'Height: ' + context.parsed.x + ' cm, Weight: ' + context.parsed.y + ' kg';
}
return label;
}
}
}
}
}
});
}
// Initial calculation on page load with default values
document.addEventListener('DOMContentLoaded', function() {
// Ensure Chart.js is loaded before trying to use it
if (typeof Chart === 'undefined') {
console.error("Chart.js is not loaded. Please include Chart.js library.");
// Optionally, disable chart-related functionality or show a message
return;
}
calculatePercentile(); // Calculate with default values
// Toggle FAQ answers
var faqQuestions = document.querySelectorAll('.faq-question');
faqQuestions.forEach(function(question) {
question.addEventListener('click', function() {
var faqItem = this.parentElement;
faqItem.classList.toggle('open');
});
});
});