Rubber Weight Calculator
Effortlessly calculate the weight of rubber based on its dimensions and density.
Cuboid
Cylinder
Sphere
Enter the length of the rubber object.
Enter the width of the rubber object.
Enter the height of the rubber object.
Typical range: 900-1500 kg/m³.
Metric (kg, m)
Imperial (lbs, ft)
Calculation Results
–.–
Volume:
–.–
Density (input):
–.–
Unit System:
—
Formula: Weight = Volume × Density. Volume is calculated based on the selected shape (Cuboid: L×W×H; Cylinder: π×r²×h; Sphere: (4/3)×π×r³).
Weight vs. Density Relationship
This chart visualizes how rubber weight changes with varying densities for a fixed volume (e.g., a 1 m³ cuboid).
| Rubber Type | Density (kg/m³) | Applications |
|---|---|---|
| Natural Rubber (NR) | 920 – 1000 | Tires, hoses, seals, vibration dampeners |
| Styrene-Butadiene Rubber (SBR) | 950 – 1150 | Tires, footwear, industrial goods |
| Nitrile Rubber (NBR) | 1000 – 1200 | O-rings, seals, fuel hoses, oil-resistant applications |
| Ethylene Propylene Diene Monomer (EPDM) | 900 – 1200 | Automotive seals, roofing membranes, electrical insulation |
| Silicone Rubber (VMQ) | 1100 – 1400 | Medical devices, cookware, seals in extreme temperatures |
| Neoprene (CR) | 900 – 1100 | Wetsuits, hoses, belts, general-purpose rubber goods |
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What is a Rubber Weight Calculator?
A rubber weight calculator is a specialized tool designed to estimate the mass or weight of a rubber component based on its physical dimensions (volume) and its material density. This calculator simplifies the complex calculations often required in engineering, manufacturing, and material science, allowing users to quickly determine how much a piece of rubber will weigh. It is crucial for various applications, from shipping and logistics to material estimation for production runs and structural integrity analysis.
Who Should Use It?
- Engineers and Designers: To estimate the weight of rubber parts in product designs for mass budgeting, structural load calculations, and material procurement.
- Manufacturers: To determine the amount of raw rubber material needed for production batches, aiding in inventory management and cost control.
- Logistics and Shipping Professionals: To accurately calculate shipping costs and ensure compliance with weight restrictions for rubber products.
- Procurement Specialists: To estimate material quantities and associated costs for purchasing raw rubber or finished components.
- Hobbyists and DIY Enthusiasts: Who may need to calculate the weight of custom rubber parts for projects.
Common Misconceptions:
- Density is Constant: Many believe all rubber has the same density. In reality, density varies significantly depending on the type of rubber compound and any additives used. Our calculator allows for variable density input to account for this.
- Weight is Only About Size: While volume is a key factor, the material's density plays an equally important role. A large piece of low-density rubber can weigh less than a smaller piece of high-density rubber.
- Imperial vs. Metric are Interchangeable: Simply converting measurements does not always account for the correct density units. Our calculator handles unit conversions to ensure accuracy.
Rubber Weight Calculator Formula and Mathematical Explanation
The fundamental principle behind the rubber weight calculator is the relationship between mass, volume, and density, often expressed by the formula:
Mass = Volume × Density
This formula allows us to calculate the weight (mass) of the rubber component. The complexity lies in accurately determining the volume based on the shape of the rubber object and ensuring consistent units.
Step-by-Step Derivation:
- Determine the Shape: The first step is to identify the geometric shape of the rubber component (e.g., cuboid, cylinder, sphere).
- Calculate Volume: Based on the shape, use the appropriate geometric formula:
- Cuboid: Volume = Length × Width × Height
- Cylinder: Volume = π × (Radius)² × Height (where Radius = Diameter / 2)
- Sphere: Volume = (4/3) × π × (Radius)³ (where Radius = Diameter / 2)
- Ensure Consistent Units: The volume and density units must be compatible. For example, if density is in kilograms per cubic meter (kg/m³), the volume must be in cubic meters (m³). If density is in pounds per cubic foot (lbs/ft³), volume must be in cubic feet (ft³). Our calculator automatically handles these conversions when you select your preferred units.
- Calculate Weight: Multiply the calculated volume by the specified density of the rubber material.
Variable Explanations:
| Variable | Meaning | Unit (Metric) | Unit (Imperial) | Typical Range (Metric) |
|---|---|---|---|---|
| Length (L) | The longest dimension of a cuboid or the height of a cylinder. | Meters (m) | Feet (ft) | 0.01 – 10+ m |
| Width (W) | The dimension perpendicular to length for a cuboid. | Meters (m) | Feet (ft) | 0.01 – 10+ m |
| Height (H) | The vertical dimension for cuboids and cylinders. | Meters (m) | Feet (ft) | 0.01 – 10+ m |
| Radius (r) | Distance from the center to the edge of a circle (used for cylinders and spheres). | Meters (m) | Feet (ft) | 0.005 – 5+ m |
| Density (ρ) | Mass per unit volume of the rubber material. | Kilograms per cubic meter (kg/m³) | Pounds per cubic foot (lbs/ft³) | 900 – 1500 kg/m³ (approx.) |
| Volume (V) | The three-dimensional space occupied by the rubber object. | Cubic meters (m³) | Cubic feet (ft³) | Calculated based on dimensions |
| Weight (W) | The force exerted on the rubber object due to gravity (often used interchangeably with mass in common language). | Kilograms (kg) | Pounds (lbs) | Calculated based on inputs |
Practical Examples (Real-World Use Cases)
Understanding the rubber weight calculator is best done through practical scenarios:
Example 1: Calculating Weight for a Tire Manufacturer
A manufacturer is producing a specific type of industrial tire. The tire can be approximated as a large cylinder with a hole in the middle (annulus), but for simplicity, we'll consider the main rubber volume. Let's assume the rubber part before vulcanization is roughly cylindrical.
- Inputs:
- Shape: Cylinder
- Diameter: 1.2 meters (Radius = 0.6 m)
- Height (Tread Width): 0.3 meters
- Rubber Density (SBR Blend): 1100 kg/m³
- Units: Metric
- Calculation using the calculator:
- Volume = π × (0.6 m)² × 0.3 m ≈ 0.339 m³
- Weight = 0.339 m³ × 1100 kg/m³ ≈ 373 kg
- Interpretation: Each tire requires approximately 373 kg of raw rubber material. This figure is vital for planning raw material purchases, calculating production costs, and estimating the shipping weight of the finished product.
Example 2: Estimating Weight for a Rubber Seal
An engineer is designing a custom rubber seal for a high-pressure application. The seal is a rectangular block.
- Inputs:
- Shape: Cuboid
- Length: 0.5 meters
- Width: 0.1 meters
- Height: 0.02 meters
- Rubber Density (Nitrile Rubber – NBR): 1150 kg/m³
- Units: Metric
- Calculation using the calculator:
- Volume = 0.5 m × 0.1 m × 0.02 m = 0.001 m³
- Weight = 0.001 m³ × 1150 kg/m³ = 1.15 kg
- Interpretation: Each custom seal weighs 1.15 kg. If they need to produce 1000 seals, they would require 1150 kg of NBR rubber. This helps in accurate quoting and material management for the production run.
How to Use This Rubber Weight Calculator
Using our rubber weight calculator is straightforward and requires just a few inputs. Follow these steps:
- Select Rubber Shape: Choose the geometric shape that best represents your rubber component from the dropdown menu (Cuboid, Cylinder, or Sphere).
- Enter Dimensions: Input the relevant dimensions (Length, Width, Height, or Radius) for the selected shape. Ensure you use consistent units.
- Input Rubber Density: Enter the density of the specific rubber compound you are using. Typical values are provided as a guide, but it's best to use the exact density if known.
- Choose Units: Select whether you are working in Metric (kilograms, meters) or Imperial (pounds, feet). The calculator will use these units for input and output.
- View Results: The calculator will automatically update in real-time, displaying:
- Primary Result: The calculated total weight of the rubber.
- Volume: The calculated volume of the rubber component.
- Density: The density value you entered.
- Unit System: The selected unit system.
- Interpret Results: Use the calculated weight for material estimation, cost analysis, shipping, or design adjustments.
- Reset or Copy: Use the "Reset" button to clear all fields and start over. Use the "Copy Results" button to copy the key figures to your clipboard.
Decision-Making Guidance:
- Material Selection: If the calculated weight is too high for your application (e.g., due to shipping constraints), consider using a rubber compound with lower density, provided it meets other performance requirements.
- Cost Estimation: Multiply the calculated weight by the cost per unit mass of the rubber material to estimate raw material expenses.
- Design Optimization: Adjusting dimensions can significantly alter the weight. Use the calculator to find the optimal balance between size, weight, and performance.
Key Factors That Affect Rubber Weight Results
Several factors influence the calculated weight of a rubber component:
- Geometric Shape and Dimensions: This is the most direct factor. Larger dimensions and more complex shapes generally result in greater volume and, consequently, higher weight. This is the primary input for our rubber weight calculator.
- Rubber Density: Different types of rubber polymers (e.g., Natural Rubber, SBR, NBR, Silicone) have distinct densities due to their molecular structure and composition. Higher density rubbers will always weigh more for the same volume. Choosing the right rubber compound is crucial for meeting weight targets.
- Fillers and Additives: Many rubber formulations include fillers like carbon black, silica, or calcium carbonate to enhance properties (strength, abrasion resistance) or reduce cost. These additives can significantly alter the final density and, therefore, the weight of the rubber compound.
- Temperature: While the effect is usually minor within typical operating ranges, extreme temperatures can cause rubber to expand or contract slightly, altering its volume and, thus, its weight per unit volume (density).
- Vulcanization Process: The curing process (vulcanization) involves chemical reactions that cross-link the polymer chains. This process can sometimes lead to slight changes in volume and density.
- Air or Gas Inclusion: Foamed or cellular rubber products contain voids filled with air or gas, significantly reducing their overall density and weight compared to solid rubber. This calculator assumes solid rubber unless otherwise accounted for by a lower input density.
- Unit System Consistency: Using incorrect unit conversions (e.g., mixing meters and centimeters without proper calculation) will lead to drastically inaccurate weight calculations. Our calculator ensures consistency once the unit system is selected.
Frequently Asked Questions (FAQ)
What is the typical density of rubber?
The density of rubber varies widely depending on the type and formulation. It generally ranges from about 900 kg/m³ to 1500 kg/m³. Natural rubber is typically around 920-1000 kg/m³, while denser synthetic rubbers like silicone or nitrile can be higher.
Does temperature affect the weight of rubber?
Slightly. As temperature changes, rubber can expand or contract, altering its volume. Since density is mass per unit volume, a change in volume will slightly change the weight for a constant mass, or change the mass for a constant volume. However, this effect is usually negligible for most practical applications.
Can I calculate the weight of foamed rubber with this tool?
Yes, but you must input the actual, lower density of the foamed rubber. Foamed rubber has significantly lower density due to trapped air pockets. You would need to know the specific density value for your foamed rubber product.
What's the difference between mass and weight in this context?
In everyday language and for most engineering calculations on Earth, mass and weight are often used interchangeably. Technically, mass is the amount of matter, while weight is the force of gravity on that mass. Our calculator computes mass (in kg or lbs), which is directly proportional to weight.
Why are there different units available (Metric/Imperial)?
Different regions and industries use different measurement systems. Providing both metric (kilograms, meters) and imperial (pounds, feet) options ensures the calculator is accessible and useful to a broader range of users worldwide.
How accurate is the rubber weight calculator?
The accuracy depends entirely on the accuracy of the input values, particularly the rubber density and the dimensions. The geometric formulas used are precise for ideal shapes. For irregularly shaped rubber parts, approximations or multiple calculations might be needed.
Can this calculator be used for rubber sheeting?
Yes. If you have rubber sheeting, you can treat it as a very thin cuboid. Input the length, width, and the thickness of the sheet as the height. Ensure your units are consistent.
What if my rubber part has a complex shape?
For complex or irregular shapes, you might need to:
1. Break the shape down into simpler geometric components (e.g., a base cuboid plus attached cylinders).
2. Calculate the volume and weight of each component separately and sum them up.
3. Use water displacement method to find the volume experimentally if precise calculation is difficult.
This calculator is best suited for standard geometric forms.
How does adding fillers like carbon black affect rubber weight?
Fillers like carbon black or silica are typically denser than the base rubber polymer. Adding them increases the overall density of the rubber compound, thus increasing its weight for a given volume, while also enhancing its mechanical properties.
Related Tools and Internal Resources
Enter the length in ${lengthUnit}.
Enter the width in ${lengthUnit}.
Enter the height in ${lengthUnit}.
`;
} else if (shape === 'cylinder') {
dimensionInputsContainer.innerHTML += `
Enter the radius in ${radiusUnit}.
Enter the height in ${radiusUnit}.
`;
} else if (shape === 'sphere') {
dimensionInputsContainer.innerHTML += `
Enter the radius in ${radiusUnit}.
`;
}
updateUnits(); // Ensure units are correctly displayed after changing inputs
calculateWeight(); // Recalculate after changing inputs
}
function validateInputs() {
var isValid = true;
var units = unitSelect.value;
var lengthUnit = (units === 'imperial') ? 'ft' : 'm';
var densityUnit = (units === 'imperial') ? 'lbs/ft³' : 'kg/m³';
// Reset errors
lengthError.innerText = ";
widthError.innerText = ";
heightError.innerText = ";
var radiusError = document.getElementById('radiusError');
if (radiusError) radiusError.innerText = ";
rubberDensityError.innerText = ";
var lengthVal = parseFloat(document.getElementById('length')?.value || 0);
var widthVal = parseFloat(document.getElementById('width')?.value || 0);
var heightVal = parseFloat(document.getElementById('height')?.value || 0);
var radiusVal = parseFloat(document.getElementById('radius')?.value || 0);
var densityVal = parseFloat(rubberDensityInput.value);
var shape = rubberShapeSelect.value;
if (shape === 'cuboid') {
if (isNaN(lengthVal) || lengthVal <= 0) {
lengthError.innerText = 'Length must be a positive number.';
isValid = false;
}
if (isNaN(widthVal) || widthVal <= 0) {
widthError.innerText = 'Width must be a positive number.';
isValid = false;
}
if (isNaN(heightVal) || heightVal <= 0) {
heightError.innerText = 'Height must be a positive number.';
isValid = false;
}
} else if (shape === 'cylinder') {
if (isNaN(radiusVal) || radiusVal <= 0) {
if (!radiusError) { // Ensure radiusError element exists
radiusError = document.createElement('div');
radiusError.id = 'radiusError';
radiusError.className = 'error-message';
document.getElementById('radius').parentNode.appendChild(radiusError);
}
radiusError.innerText = 'Radius must be a positive number.';
isValid = false;
}
if (isNaN(heightVal) || heightVal <= 0) {
heightError.innerText = 'Height must be a positive number.';
isValid = false;
}
} else if (shape === 'sphere') {
if (isNaN(radiusVal) || radiusVal <= 0) {
if (!radiusError) { // Ensure radiusError element exists
radiusError = document.createElement('div');
radiusError.id = 'radiusError';
radiusError.className = 'error-message';
document.getElementById('radius').parentNode.appendChild(radiusError);
}
radiusError.innerText = 'Radius must be a positive number.';
isValid = false;
}
}
if (isNaN(densityVal) || densityVal <= 0) {
rubberDensityError.innerText = 'Density must be a positive number.';
isValid = false;
}
return isValid;
}
function calculateVolume() {
var shape = rubberShapeSelect.value;
var volume = 0;
var units = unitSelect.value;
var lengthUnit = (units === 'imperial') ? 'ft' : 'm';
if (shape === 'cuboid') {
var length = parseFloat(document.getElementById('length')?.value || 0);
var width = parseFloat(document.getElementById('width')?.value || 0);
var height = parseFloat(document.getElementById('height')?.value || 0);
if (!isNaN(length) && !isNaN(width) && !isNaN(height)) {
volume = length * width * height;
}
} else if (shape === 'cylinder') {
var radius = parseFloat(document.getElementById('radius')?.value || 0);
var height = parseFloat(document.getElementById('height')?.value || 0);
if (!isNaN(radius) && !isNaN(height)) {
volume = Math.PI * Math.pow(radius, 2) * height;
}
} else if (shape === 'sphere') {
var radius = parseFloat(document.getElementById('radius')?.value || 0);
if (!isNaN(radius)) {
volume = (4 / 3) * Math.PI * Math.pow(radius, 3);
}
}
// Format volume to 3 decimal places
volume = parseFloat(volume.toFixed(3));
volumeResultElement.innerText = volume.toLocaleString() + ' ' + (lengthUnit === 'ft' ? 'ft³' : 'm³');
return volume;
}
function calculateWeight() {
if (!validateInputs()) {
primaryResultElement.innerText = '–.–';
return;
}
var volume = calculateVolume();
var density = parseFloat(rubberDensityInput.value);
var units = unitSelect.value;
var weight = 0;
var weightUnit = 'kg';
if (units === 'imperial') {
// If user selected Imperial, assume density is also provided in imperial units (lbs/ft³)
// If density was entered in kg/m³, a conversion would be needed here.
// For simplicity, let's proceed assuming density unit matches selected unit system.
weight = volume * density; // Assuming volume is in ft³ and density in lbs/ft³
weightUnit = 'lbs';
} else { // Metric
weight = volume * density; // Assuming volume is in m³ and density in kg/m³
weightUnit = 'kg';
}
// Format weight to 2 decimal places
weight = parseFloat(weight.toFixed(2));
primaryResultElement.innerText = weight.toLocaleString() + ' ' + weightUnit;
densityResultElement.innerText = density.toLocaleString() + ' ' + (units === 'imperial' ? 'lbs/ft³' : 'kg/m³');
unitResultElement.innerText = units.charAt(0).toUpperCase() + units.slice(1);
updateChart();
}
function resetCalculator() {
document.getElementById('rubberShape').value = 'cuboid';
document.getElementById('unit').value = 'metric';
updateInputs(); // Re-renders the inputs based on default shape and units
// Set default sensible values after updateInputs has run
document.getElementById('length').value = '1';
document.getElementById('width').value = '0.5';
document.getElementById('height').value = '0.1';
document.getElementById('radius').value = ''; // Clear radius if not needed
document.getElementById('rubberDensity').value = '1100';
// Clear error messages
document.getElementById('lengthError').innerText = '';
document.getElementById('widthError').innerText = '';
document.getElementById('heightError').innerText = '';
if (document.getElementById('radiusError')) document.getElementById('radiusError').innerText = '';
document.getElementById('rubberDensityError').innerText = '';
calculateWeight();
}
function copyResults() {
var mainResult = primaryResultElement.innerText;
var volumeResult = volumeResultElement.innerText;
var densityResult = densityResultElement.innerText;
var unitResult = unitResultElement.innerText;
var shape = rubberShapeSelect.value;
var selectedUnit = unitSelect.value;
var assumptions = "Shape: " + shape.charAt(0).toUpperCase() + shape.slice(1) + "\n";
assumptions += "Units: " + unitResult + "\n";
if (selectedUnit === 'metric') {
assumptions += "Length: " + (document.getElementById('length')?.value || '–') + " m\n";
assumptions += "Width: " + (document.getElementById('width')?.value || '–') + " m\n";
assumptions += "Height: " + (document.getElementById('height')?.value || '–') + " m\n";
if (document.getElementById('radius')) assumptions += "Radius: " + (document.getElementById('radius')?.value || '–') + " m\n";
} else {
assumptions += "Length: " + (document.getElementById('length')?.value || '–') + " ft\n";
assumptions += "Width: " + (document.getElementById('width')?.value || '–') + " ft\n";
assumptions += "Height: " + (document.getElementById('height')?.value || '–') + " ft\n";
if (document.getElementById('radius')) assumptions += "Radius: " + (document.getElementById('radius')?.value || '–') + " ft\n";
}
assumptions += "Rubber Density: " + (document.getElementById('rubberDensity')?.value || '–') + (selectedUnit === 'metric' ? ' kg/m³' : ' lbs/ft³') + "\n";
var textToCopy = "— Rubber Weight Calculation —\n\n";
textToCopy += "Resulting Weight: " + mainResult + "\n";
textToCopy += "Calculated Volume: " + volumeResult + "\n";
textToCopy += "Input Density: " + densityResult + "\n";
textToCopy += "\n— Key Assumptions —\n" + assumptions;
navigator.clipboard.writeText(textToCopy).then(function() {
// Success feedback (optional)
var originalText = event.target.innerText;
event.target.innerText = 'Copied!';
setTimeout(function(){ event.target.innerText = originalText; }, 1500);
}, function(err) {
console.error('Failed to copy text: ', err);
// Error feedback (optional)
});
}
function initChart() {
var ctx = document.getElementById('weightDensityChart').getContext('2d');
chart = new Chart(ctx, {
type: 'line',
data: chartData,
options: {
responsive: true,
maintainAspectRatio: true,
scales: {
x: {
title: {
display: true,
text: 'Density (kg/m³)'
}
},
y: { // Primary y-axis for Weight
type: 'linear',
position: 'left',
title: {
display: true,
text: 'Weight (kg)'
},
ticks: {
beginAtZero: true
}
},
'y-axis-density': { // Secondary y-axis for Density (if needed, but we use x-axis for density here)
// We are using density on the X-axis for this specific chart relationship
display: false // Hide if not using a second Y axis for density
}
},
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Rubber Weight vs. Density (Fixed Volume)'
}
}
}
});
}
function updateChart() {
if (!chart) initChart();
var baseVolume = calculateVolume(); // Get current volume
var currentUnits = unitSelect.value;
var densityMax = (currentUnits === 'imperial') ? 150 / 0.0624 : 1500; // Set a reasonable max density for the chart
var densityStep = densityMax / 10;
var fixedVolumeMetric = baseVolume; // Assume baseVolume is in m³ for chart calculation
if (currentUnits === 'imperial') {
// Convert current volume to m³ for consistent chart calculation if needed
// This part requires careful unit conversion logic.
// For simplicity, let's assume the chart always uses metric units for density and weight calculation internal logic.
// User inputs in imperial will be converted internally for chart population.
// Example: 1 ft³ = 0.0283168 m³
// Example: 1 lb = 0.453592 kg
// Density conversion: 1 lb/ft³ = 16.0185 kg/m³
var currentDensityImperial = parseFloat(rubberDensityInput.value);
fixedVolumeMetric = baseVolume * 0.0283168; // Convert current volume to m³ if input was imperial
}
chartData.labels = [];
chartData.datasets[0].data = []; // Weight data
chartData.datasets[1].data = []; // Density data (will be plotted on x-axis)
for (var i = 900; i <= densityMax; i += densityStep) { // Start from a lower density value for clarity
var densityValue = parseFloat(i.toFixed(0));
var weightValue = 0;
if (currentUnits === 'imperial') {
// Calculate weight using converted metric volume and metric density, then convert weight to lbs
var metricDensity = densityValue; // Assuming chart density is metric kg/m³
var weightInKg = fixedVolumeMetric * metricDensity;
weightValue = weightInKg * 2.20462; // Convert kg to lbs
} else {
// Calculate weight directly using metric volume and metric density
weightValue = fixedVolumeMetric * densityValue; // kg
}
chartData.labels.push(densityValue.toFixed(0));
chartData.datasets[0].data.push(parseFloat(weightValue.toFixed(2))); // Push weight value
chartData.datasets[1].data.push(densityValue); // Push density value for x-axis context
}
// Ensure the current calculated weight/density is shown, even if slightly outside the range
var currentDensityForChart = parseFloat(rubberDensityInput.value);
var currentWeightForChart = parseFloat(primaryResultElement.innerText.replace(/,/g, '').replace(/ lbs| kg/g, ''));
var currentVolumeForChartMetric = calculateVolume() * (currentUnits === 'imperial' ? 0.0283168 : 1); // Ensure volume is in m³
var densityExists = chartData.labels.map(Number).includes(currentDensityForChart);
if (!densityExists) {
var weightToAdd = 0;
if (currentUnits === 'imperial') {
weightToAdd = currentVolumeForChartMetric * currentDensityForChart * 2.20462; // kg to lbs
} else {
weightToAdd = currentVolumeForChartMetric * currentDensityForChart; // kg
}
chartData.labels.push(currentDensityForChart.toFixed(0));
chartData.datasets[0].data.push(parseFloat(weightToAdd.toFixed(2)));
chartData.datasets[1].data.push(currentDensityForChart);
}
// Sort data by density (X-axis)
var combined = [];
for (var i = 0; i < chartData.labels.length; i++) {
combined.push({ label: chartData.labels[i], weight: chartData.datasets[0].data[i], density: chartData.datasets[1].data[i] });
}
combined.sort(function(a, b) { return a.density – b.density; });
chartData.labels = combined.map(function(item) { return item.label; });
chartData.datasets[0].data = combined.map(function(item) { return item.weight; });
chartData.datasets[1].data = combined.map(function(item) { return item.density; }); // Update density data as well
chart.update();
}
// Initial setup
document.addEventListener('DOMContentLoaded', function() {
initChart();
updateInputs(); // Set up the correct initial input fields
updateUnits(); // Set up the correct initial unit display
calculateWeight(); // Perform initial calculation
setupFAQ();
});
function setupFAQ() {
var faqItems = document.querySelectorAll('.faq-item .question');
for (var i = 0; i < faqItems.length; i++) {
faqItems[i].addEventListener('click', function() {
this.parentNode.classList.toggle('open');
});
}
}