Magnet Weight Calculator
Precisely determine the mass of any magnet based on its dimensions and material density.
Magnet Specifications
Cuboid
Cylinder
Sphere
Select the geometric shape of your magnet.
Enter the length of the magnet in centimeters (cm).
Enter the width of the magnet in centimeters (cm).
Enter the height of the magnet in centimeters (cm).
Steel (approx.)
Aluminum (approx.)
Neodymium Magnet (NdFeB, approx.)
Samarium Cobalt Magnet (SmCo, approx.)
Gold (approx.)
Lead (approx.)
Custom
Density unit: g/cm³
Your Magnet's Weight
—- Magnet Volume: —
- Magnet Mass: —
- Density Used: —
Formula Explanation
Weight (Mass) = Volume × Density
Volume is calculated based on the magnet's shape and dimensions.
Volume vs. Weight for Different Densities
Comparison of magnet weight for a fixed volume across various common material densities.
Magnet Weight Distribution by Dimension
How changing individual dimensions affects the total magnet weight, assuming other dimensions and density remain constant.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Length (L), Width (W), Height (H) | Dimensions of the magnet | cm | 0.001 – 1000 |
| Radius (r) | Radius of the cylindrical or spherical magnet | cm | 0.001 – 1000 |
| Volume (V) | The space occupied by the magnet | cm³ | Varies based on dimensions |
| Density (ρ) | Mass per unit volume of the magnet material | g/cm³ | 0.01 – 50 |
| Weight (Mass) (m) | The calculated mass of the magnet | grams (g) | Varies based on inputs |
Magnet Weight Calculator: Understanding Magnet Mass
What is Magnet Weight Calculation?
{primary_keyword} is the process of determining the mass (commonly referred to as weight) of a magnetic object based on its physical dimensions and the density of the material it's made from. Magnets come in various shapes (cuboids, cylinders, spheres) and are constructed from different materials, each possessing a unique density. Accurate calculation is crucial for applications ranging from industrial manufacturing and engineering to scientific research and even hobbyist projects, ensuring proper handling, integration into systems, and cost estimation.
Who Should Use It:
- Engineers and Designers: For structural integrity, mounting requirements, and integration into larger systems where mass is a critical factor.
- Manufacturers: For quality control, material estimation, and cost analysis in production.
- Researchers: In physics and material science for experiments and simulations involving magnetic fields and material properties.
- Procurement Specialists: To estimate material quantities and costs for purchasing magnets.
- Hobbyists and Educators: For understanding magnetic properties and engaging in practical physics experiments.
Common Misconceptions:
- Weight vs. Magnetic Force: A magnet's weight is its mass due to gravity, completely unrelated to its magnetic pulling force. A small, dense magnet might be heavy but have weak magnetism, while a larger, less dense magnet might be lighter but much stronger magnetically.
- Density is Constant: While densities for common materials are well-known, slight variations can occur due to manufacturing processes, purity, and temperature. Our calculator uses standard values, but precise applications might require specific material data.
- Units Matter: Confusing units (e.g., using inches for dimensions but grams/cm³ for density) will lead to incorrect weight calculations. Consistency is key.
Magnet Weight Formula and Mathematical Explanation
The fundamental principle behind calculating the weight (or more accurately, mass) of any object, including a magnet, is the relationship between its volume, density, and mass. The formula is straightforward:
The Core Formula: Mass = Volume × Density
Let's break down each component:
- Mass (m): This is what we are trying to calculate – the total amount of matter in the magnet. We typically express this in grams (g) or kilograms (kg).
- Volume (V): This is the three-dimensional space the magnet occupies. The calculation of volume depends entirely on the magnet's shape.
- Density (ρ): This is an intrinsic property of the material the magnet is made from. It represents how much mass is contained within a specific unit of volume. Common units are grams per cubic centimeter (g/cm³).
Volume Calculations Based on Shape:
- Cuboid Magnet: The volume is calculated by multiplying its three dimensions:
V = Length × Width × Height - Cylindrical Magnet: The volume is calculated using the formula for a cylinder:
V = π × radius² × heightWhere 'π' (pi) is approximately 3.14159. - Spherical Magnet: The volume is calculated using the formula for a sphere:
V = (4/3) × π × radius³
By calculating the volume first (ensuring all dimensions are in consistent units, like centimeters) and then multiplying it by the material's density (in compatible units, like g/cm³), we arrive at the magnet's mass in grams.
Variable Explanations & Table:
Here's a detailed look at the variables involved in the magnet weight calculator and their typical ranges:
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Length (L), Width (W), Height (H) | Orthogonal dimensions of a cuboid magnet. | cm | 0.001 – 1000 |
| Radius (r) | The distance from the center to the edge for cylindrical or spherical magnets. | cm | 0.001 – 1000 |
| Volume (V) | The amount of space the magnet occupies. Calculated based on shape. | cm³ | Calculated value, depends on dimensions |
| Density (ρ) | Mass per unit volume of the magnet's material. | g/cm³ | 0.01 – 50 (e.g., 7.2 for NdFeB, 2.7 for Aluminum) |
| Weight (Mass) (m) | The final calculated mass of the magnet. | grams (g) | Calculated value, depends on inputs |
This detailed breakdown ensures clarity when using the magnet weight calculator, helping users understand the inputs and the resulting output.
Practical Examples (Real-World Use Cases)
Understanding the magnet weight calculator is best done through practical examples:
Example 1: Calculating the Weight of a Neodymium Magnet
A customer needs to know the weight of a block-shaped neodymium magnet for a specific mounting bracket. The dimensions are:
- Length (L): 3 cm
- Width (W): 2 cm
- Height (H): 1 cm
- Material: Neodymium Magnet (NdFeB)
Using the calculator:
- Inputs: Length=3 cm, Width=2 cm, Height=1 cm, Density=7.20 g/cm³ (standard for NdFeB).
- Calculation:
- Volume = 3 cm × 2 cm × 1 cm = 6 cm³
- Mass = Volume × Density = 6 cm³ × 7.20 g/cm³ = 43.2 grams
- Result: The neodymium magnet weighs 43.2 grams. This information is vital for ensuring the mounting bracket can support the weight and that shipping costs are accurately estimated. This is a key use case for the magnet weight calculator in supply chain management.
Example 2: Calculating the Weight of a Large Ferrite Magnet
An industrial client is considering using a large, disc-shaped ferrite magnet in a motor assembly. They need to estimate its weight.
- Shape: Cylinder
- Diameter: 10 cm (so Radius = 5 cm)
- Height: 4 cm
- Material: Ferrite (Density ≈ 4.9 g/cm³)
Using the calculator:
- Inputs: Radius=5 cm, Height=4 cm, Density=4.9 g/cm³ (typical for Ferrite).
- Calculation:
- Volume = π × (5 cm)² × 4 cm = π × 25 cm² × 4 cm ≈ 3.14159 × 100 cm³ ≈ 314.16 cm³
- Mass = Volume × Density = 314.16 cm³ × 4.9 g/cm³ ≈ 1539.4 grams (or 1.54 kg)
- Result: The ferrite disc magnet weighs approximately 1539.4 grams. This substantial weight impacts the motor's overall design, including bearing load capacity and structural support considerations. Accurate magnet weight calculator results prevent costly design flaws.
How to Use This Magnet Weight Calculator
Our intuitive magnet weight calculator simplifies the process of finding a magnet's mass. Follow these simple steps:
- Select Magnet Shape: Choose 'Cuboid', 'Cylinder', or 'Sphere' from the dropdown menu.
- Enter Dimensions:
- For Cuboids: Input the Length, Width, and Height in centimeters (cm).
- For Cylinders: Input the Radius and Height in centimeters (cm).
- For Spheres: Input the Radius in centimeters (cm). (Note: The calculator adjusts input fields dynamically).
- Select Material Density: Choose a common magnet material from the dropdown (e.g., Neodymium, Samarium Cobalt) or select 'Custom' to manually enter the density in g/cm³. The unit (g/cm³) is displayed for clarity.
- Calculate: Click the "Calculate Weight" button.
Reading the Results:
- Primary Result (Highlighted): This displays the calculated magnet weight in grams (g).
- Intermediate Values: You'll see the calculated Volume (in cm³) and the specific Density value used for the calculation.
- Formula Explanation: A brief description of the calculation (Mass = Volume × Density).
Decision-Making Guidance:
Use the calculated weight for various purposes:
- Structural Integration: Determine if mounting hardware can support the magnet's mass.
- Shipping Costs: Estimate shipping expenses accurately.
- Material Handling: Plan for necessary equipment if the magnet is very heavy.
- Cost Analysis: Relate weight to material cost, especially for expensive magnetic materials like Neodymium or Samarium Cobalt.
Don't forget the "Copy Results" button for easy transfer of data and the "Reset" button to start fresh.
Key Factors That Affect Magnet Weight Results
While the core formula (Mass = Volume × Density) is simple, several factors influence the accuracy and application of the magnet weight calculation:
- Precise Dimensions: Even small inaccuracies in measuring length, width, height, or radius can lead to noticeable differences in calculated volume and, consequently, weight. Always double-check measurements, especially for smaller magnets.
- Material Density Variations: The density values provided are typical averages. Actual densities can vary slightly based on the exact alloy composition, manufacturing process (sintering, bonding), and purity of the magnetic material. For critical applications, consult the manufacturer's specific data sheet for the precise density.
- Magnet Shape Complexity: While this calculator handles common shapes (cuboid, cylinder, sphere), magnets can have complex geometries (e.g., rings, arcs, complex profiles). Calculating the volume for these shapes requires more advanced calculus or CAD software, and their weight calculation would follow the same Mass = Volume × Density principle but with a more intricate volume derivation.
- Units Consistency: The most common error is using inconsistent units. The calculator is designed for centimeters (cm) for dimensions and grams per cubic centimeter (g/cm³) for density. Mixing units (e.g., inches, meters, kg/m³) will produce wildly incorrect results.
- Temperature Effects: While density is less affected by temperature than magnetic properties, significant thermal expansion or contraction could theoretically alter the volume slightly. However, for most practical purposes, this effect is negligible for weight calculations.
- Tolerances in Manufacturing: Real-world magnets have manufacturing tolerances for both dimensions and density. The calculated weight represents an ideal value, while the actual weight of a physical magnet might vary slightly within these tolerances. This is important for applications requiring very precise weight matching.
- Hollow Structures: If a magnet has a hollow core (like some ring magnets), the simple volume formulas won't apply directly. You would need to calculate the volume of the outer shape and subtract the volume of the hollow space. The calculator assumes solid magnets.
- Coating/Plating: Many magnets are coated (e.g., with nickel or epoxy) for protection. The weight of this coating is usually negligible compared to the magnet's core weight, but for ultra-high precision, it might need to be accounted for separately.
Frequently Asked Questions (FAQ)
What is the difference between magnet weight and magnetic force?
Magnet weight refers to its mass (how much it weighs due to gravity), determined by its volume and material density. Magnetic force (or pull strength) refers to its ability to attract ferromagnetic materials, influenced by factors like magnetic material type, size, shape, and magnetization. They are independent properties.
Does the calculator account for magnetic material types like NdFeB vs. Ferrite?
Yes, indirectly. The calculator uses the material's density, which varies significantly between types like Neodymium (NdFeB, ~7.20 g/cm³) and Ferrite (~4.9 g/cm³). You can select common types or enter a custom density if you know the exact value for your specific magnet.
What units does the calculator use?
The calculator expects dimensions (Length, Width, Height, Radius) in centimeters (cm) and density in grams per cubic centimeter (g/cm³). The resulting weight is displayed in grams (g).
Can I calculate the weight of a magnet with complex or irregular shapes?
This calculator is designed for basic geometric shapes: cuboids, cylinders, and spheres. For irregular shapes, you would need to determine the volume using methods like water displacement (Archimedes' principle) or 3D modeling software and then apply the formula: Mass = Volume × Density.
What if I don't know the exact density of my magnet material?
You can select one of the common material presets (like Neodymium or Ferrite), which use typical density values. If accuracy is paramount and these presets don't match your material, you can choose 'Custom' and enter the density value directly from the manufacturer's specifications or a reliable material database.
How accurate is the calculator?
The accuracy of the calculator depends directly on the accuracy of the input dimensions and the density value used. Assuming precise inputs, the mathematical calculation itself is highly accurate. Real-world factors like manufacturing tolerances and slight density variations may cause minor differences in the actual weight of a physical magnet.
Why are there separate charts for volume vs. weight and dimensions?
The 'Volume vs. Weight' chart illustrates how drastically different materials impact the weight of magnets with the *same* volume. The 'Dimension Chart' shows how changing just one dimension affects the weight of a magnet with *fixed* density and other dimensions, highlighting the sensitivity to size.
Does the calculator consider the weight of any coatings?
The calculator focuses on the core magnetic material's weight. Coatings like nickel plating or epoxy are typically very thin, and their contribution to the total weight is usually negligible for most applications. If coating weight is critical for your specific use case (e.g., extremely high-precision weighing), you would need to calculate it separately and add it to the results from this calculator.
Related Tools and Internal Resources
- Magnet Strength Calculator Estimate the magnetic pull force for various magnet types.
- Magnetic Field Calculator Calculate magnetic field strength at different points around a magnet.
- Demagnetization Calculator Assess the risk of a magnet losing its magnetism under certain conditions.
- Magnet Material Properties Guide Detailed information on densities, Curie temperatures, and coercivity of different magnetic materials.
- Blog Post: Weight vs. Force – What's the Real Difference? An in-depth look at two key magnet characteristics.
- Guide: Choosing the Right Magnet for Your Application Learn how factors like weight, force, and material impact your selection.
Enter the length of the magnet in centimeters (cm).
Enter the width of the magnet in centimeters (cm).
Enter the height of the magnet in centimeters (cm).
`;
} else if (shape === 'cylinder') {
shapeInputsContainer.innerHTML = `
Enter the radius of the cylinder base in centimeters (cm).
Enter the height of the cylinder in centimeters (cm).
`;
} else if (shape === 'sphere') {
shapeInputsContainer.innerHTML = `
Enter the radius of the sphere in centimeters (cm).
`;
}
// Re-apply event listeners or call update if needed after refresh
calculateWeight(); // Recalculate after changing shape
}
function updateDensityUnit() {
var selectedOption = densitySelect.options[densitySelect.selectedIndex];
var unit = selectedOption.getAttribute('data-unit') || 'g/cm³'; // Default if attribute missing
densityUnitElement.textContent = 'Density unit: ' + unit;
if (densitySelect.value === 'custom') {
customDensityInput.value = "; // Clear custom input
customDensityGroup.style.display = 'block';
validateInput(customDensityInput, 0.001, 50); // Trigger validation immediately
} else {
customDensityGroup.style.display = 'none';
document.getElementById('customDensityError').textContent = "; // Clear error
}
calculateWeight(); // Recalculate after changing density
}
function validateInput(inputElement, minValue, maxValue) {
var errorElement = document.getElementById(inputElement.id + 'Error');
var value = parseFloat(inputElement.value);
if (isNaN(value)) {
errorElement.textContent = 'Please enter a valid number.';
return false;
} else if (value <= 0) {
// Allow zero for some calculations, but weight needs positive dimensions/density
if (inputElement.id !== 'density' && inputElement.id !== 'customDensityInput' && inputElement.id !== 'length' && inputElement.id !== 'width' && inputElement.id !== 'height' && inputElement.id !== 'radius' && inputElement.id !== 'cylinderHeight' && inputElement.id !== 'sphereRadius') {
// If it's not a core dimension or density, 0 might be acceptable, but for weight, we need positive.
errorElement.textContent = 'Value must be positive.';
return false;
} else if (value maxValue) {
errorElement.textContent = 'Value cannot exceed ' + maxValue + '.';
return false;
} else {
errorElement.textContent = ";
return true;
}
}
function getInputValue(id) {
var element = document.getElementById(id);
if (!element) return NaN;
return parseFloat(element.value);
}
function calculateWeight() {
var shape = shapeSelect.value;
var volume = NaN;
var length, width, height, radius, cylinderHeight, sphereRadius;
// Clear previous errors
var errorElements = document.querySelectorAll('.error-message');
for (var i = 0; i < errorElements.length; i++) {
errorElements[i].textContent = '';
}
// Get dimensions based on shape
if (shape === 'cuboid') {
length = getInputValue('length');
width = getInputValue('width');
height = getInputValue('height');
if (!validateInput(lengthInput, 0.001, 1000) ||
!validateInput(widthInput, 0.001, 1000) ||
!validateInput(heightInput, 0.001, 1000)) {
return;
}
volume = length * width * height;
} else if (shape === 'cylinder') {
radius = getInputValue('radius');
cylinderHeight = getInputValue('cylinderHeight');
var radiusInputEl = document.getElementById('radius');
var cylinderHeightInputEl = document.getElementById('cylinderHeight');
if (!validateInput(radiusInputEl, 0.001, 1000) ||
!validateInput(cylinderHeightInputEl, 0.001, 1000)) {
return;
}
volume = Math.PI * Math.pow(radius, 2) * cylinderHeight;
} else if (shape === 'sphere') {
sphereRadius = getInputValue('sphereRadius');
var sphereRadiusInputEl = document.getElementById('sphereRadius');
if (!validateInput(sphereRadiusInputEl, 0.001, 1000)) {
return;
}
volume = (4 / 3) * Math.PI * Math.pow(sphereRadius, 3);
}
var densityValue = getInputValue('density');
if (densitySelect.value === 'custom') {
if (!validateInput(customDensityInput, 0.001, 50)) {
return;
}
densityValue = getInputValue('customDensityInput');
} else {
densityValue = parseFloat(densitySelect.value); // Use the value from the select option
}
var densityDisplay = densityValue.toFixed(2) + ' g/cm³';
if (isNaN(volume) || isNaN(densityValue) || volume <= 0 || densityValue <= 0) {
// Set default empty states if calculation is not possible
primaryResultElement.textContent = '–';
volumeResultElement.textContent = '–';
massResultElement.textContent = '–';
densityUsedResultElement.textContent = '–';
return;
}
var mass = volume * densityValue;
primaryResultElement.textContent = mass.toFixed(2) + ' g';
volumeResultElement.textContent = volume.toFixed(2) + ' cm³';
massResultElement.textContent = mass.toFixed(2) + ' g';
densityUsedResultElement.textContent = densityDisplay;
updateCharts(volume, mass); // Update charts with current values
}
function resetCalculator() {
shapeSelect.value = 'cuboid';
updateShapeInputs(); // Reset inputs for cuboid
document.getElementById('length').value = '5';
document.getElementById('width').value = '2';
document.getElementById('height').value = '1';
densitySelect.value = '7.20'; // Default to Neodymium
updateDensityUnit();
customDensityInput.value = '';
document.getElementById('customDensityError').textContent = '';
// Clear errors
var errorElements = document.querySelectorAll('.error-message');
for (var i = 0; i d.name);
var weightChartData = densitiesToCompare.map(d => {
// Calculate mass for the *current volume* with each density
var mass = currentVolume * d.value;
// Ensure mass is not NaN or Infinity before rounding
return isNaN(mass) || !isFinite(mass) ? 0 : mass;
});
if (weightChartInstance) {
weightChartInstance.destroy();
}
weightChartInstance = new Chart(chartCanvasWeight, {
type: 'bar',
data: {
labels: weightChartLabels,
datasets: [{
label: 'Magnet Mass (g)',
data: weightChartData.map(d => d.toFixed(2)), // Round for display
backgroundColor: densitiesToCompare.map(d => d.color),
borderColor: densitiesToCompare.map(d => d.color.replace('0.8', '1')),
borderWidth: 1
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Magnet Mass Comparison by Material Density (Fixed Volume)'
}
},
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Mass (grams)'
}
}
}
}
});
// — Dimension Chart —
var baseInputs = {};
var shape = shapeSelect.value;
if (shape === 'cuboid') {
baseInputs = {
length: getInputValue('length'),
width: getInputValue('width'),
height: getInputValue('height'),
density: parseFloat(densitySelect.value === 'custom' ? customDensityInput.value : densitySelect.value)
};
} else if (shape === 'cylinder') {
baseInputs = {
radius: getInputValue('radius'),
height: getInputValue('cylinderHeight'),
density: parseFloat(densitySelect.value === 'custom' ? customDensityInput.value : densitySelect.value),
isCylinder: true
};
} else if (shape === 'sphere') {
baseInputs = {
radius: getInputValue('sphereRadius'),
density: parseFloat(densitySelect.value === 'custom' ? customDensityInput.value : densitySelect.value),
isSphere: true
};
}
var dimensionChangeFactors = [0.5, 0.75, 1, 1.25, 1.5]; // Factors to multiply dimensions by
var dimensionChartLabels = dimensionChangeFactors.map(f => (f * 100) + '%');
var dimensionChartDataLength = [];
var dimensionChartDataWidth = [];
var dimensionChartDataHeight = [];
dimensionChangeFactors.forEach(function(factor) {
var tempMass = 0;
var tempVolume = 0;
var currentDensityVal = baseInputs.density;
if (shape === 'cuboid') {
var l = baseInputs.length * factor;
var w = baseInputs.width * factor;
var h = baseInputs.height * factor;
if (l > 0 && w > 0 && h > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = l * w * h;
tempMass = tempVolume * currentDensityVal;
}
dimensionChartDataLength.push(tempMass);
// Assume width is the dimension being changed for this series
l = baseInputs.length;
w = baseInputs.width * factor;
h = baseInputs.height;
if (l > 0 && w > 0 && h > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = l * w * h;
dimensionChartDataWidth.push(tempVolume * currentDensityVal);
} else { dimensionChartDataWidth.push(0);}
// Assume height is the dimension being changed
l = baseInputs.length;
w = baseInputs.width;
h = baseInputs.height * factor;
if (l > 0 && w > 0 && h > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = l * w * h;
dimensionChartDataHeight.push(tempVolume * currentDensityVal);
} else { dimensionChartDataHeight.push(0); }
} else if (shape === 'cylinder') {
var r = baseInputs.radius * factor;
var h = baseInputs.height; // Keep height constant for radius change
if (r > 0 && h > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = Math.PI * Math.pow(r, 2) * h;
tempMass = tempVolume * currentDensityVal;
}
dimensionChartDataLength.push(tempMass); // Using "Length" dataset for radius change effect
// Assume height is the dimension being changed
r = baseInputs.radius;
h = baseInputs.height * factor;
if (r > 0 && h > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = Math.PI * Math.pow(r, 2) * h;
dimensionChartDataWidth.push(tempVolume * currentDensityVal); // Using "Width" dataset for height change effect
} else { dimensionChartDataWidth.push(0); }
dimensionChartDataHeight.push(0); // No third dimension for cylinder
} else if (shape === 'sphere') {
var r = baseInputs.radius * factor;
if (r > 0 && !isNaN(currentDensityVal) && currentDensityVal > 0) {
tempVolume = (4 / 3) * Math.PI * Math.pow(r, 3);
tempMass = tempVolume * currentDensityVal;
}
dimensionChartDataLength.push(tempMass); // Using "Length" dataset for radius change effect
dimensionChartDataWidth.push(0); // No width for sphere
dimensionChartDataHeight.push(0); // No height for sphere
}
});
if (dimensionChartInstance) {
dimensionChartInstance.destroy();
}
var dimensionLabels = ['Dimension 1', 'Dimension 2', 'Dimension 3'];
var dimensionDataSeries = [];
if (shape === 'cuboid') {
dimensionDataSeries.push({
label: 'Length Change Effect',
data: dimensionChartDataLength.map(d => d.toFixed(2)),
borderColor: 'rgba(0, 74, 153, 1)',
backgroundColor: 'rgba(0, 74, 153, 0.5)',
fill: false
});
dimensionDataSeries.push({
label: 'Width Change Effect',
data: dimensionChartDataWidth.map(d => d.toFixed(2)),
borderColor: 'rgba(40, 167, 69, 1)',
backgroundColor: 'rgba(40, 167, 69, 0.5)',
fill: false
});
dimensionDataSeries.push({
label: 'Height Change Effect',
data: dimensionChartDataHeight.map(d => d.toFixed(2)),
borderColor: 'rgba(255, 193, 7, 1)',
backgroundColor: 'rgba(255, 193, 7, 0.5)',
fill: false
});
} else if (shape === 'cylinder') {
dimensionDataSeries.push({
label: 'Radius Change Effect',
data: dimensionChartDataLength.map(d => d.toFixed(2)), // Using Length dataset for radius
borderColor: 'rgba(0, 74, 153, 1)',
backgroundColor: 'rgba(0, 74, 153, 0.5)',
fill: false
});
dimensionDataSeries.push({
label: 'Height Change Effect',
data: dimensionChartDataWidth.map(d => d.toFixed(2)), // Using Width dataset for height
borderColor: 'rgba(40, 167, 69, 1)',
backgroundColor: 'rgba(40, 167, 69, 0.5)',
fill: false
});
} else if (shape === 'sphere') {
dimensionDataSeries.push({
label: 'Radius Change Effect',
data: dimensionChartDataLength.map(d => d.toFixed(2)), // Using Length dataset for radius
borderColor: 'rgba(0, 74, 153, 1)',
backgroundColor: 'rgba(0, 74, 153, 0.5)',
fill: false
});
}
dimensionChartInstance = new Chart(chartCanvasDimension, {
type: 'line', // Line chart works well for showing trends across factors
data: {
labels: dimensionChartLabels,
datasets: dimensionDataSeries
},
options: {
responsive: true,
maintainAspectRatio: false,
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Magnet Weight Change by Dimension Scaling'
}
},
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Mass (grams)'
}
},
x: {
title: {
display: true,
text: 'Dimension Scale Factor'
}
}
}
}
});
}
// Initial calculation and chart rendering on page load
document.addEventListener('DOMContentLoaded', function() {
updateShapeInputs(); // Set up initial shape inputs
updateDensityUnit(); // Set up initial density unit display
resetCalculator(); // Load default values and perform initial calculation
// Call updateCharts explicitly after resetCalculator has set initial values
// to ensure charts are drawn based on defaults.
var initialVolume = parseFloat(volumeResultElement.textContent);
var initialMass = parseFloat(massResultElement.textContent);
if (!isNaN(initialVolume) && !isNaN(initialMass)) {
updateCharts(initialVolume, initialMass);
} else {
// If initial values are '–', try to calculate based on defaults set in resetCalculator
// This might require getting default input values directly if resetCalculator doesn't update the elements immediately
var defaultLength = parseFloat(document.getElementById('length').value) || 5;
var defaultWidth = parseFloat(document.getElementById('width').value) || 2;
var defaultHeight = parseFloat(document.getElementById('height').value) || 1;
var defaultVolume = defaultLength * defaultWidth * defaultHeight;
var defaultDensity = parseFloat(densitySelect.value);
var defaultMass = defaultVolume * defaultDensity;
updateCharts(defaultVolume, defaultMass);
}
});
function toggleFaq(element) {
var content = element.nextElementSibling;
var allContents = element.parentNode.parentNode.querySelectorAll('.faq-item p');
for (var i = 0; i < allContents.length; i++) {
if (allContents[i] !== content) {
allContents[i].style.display = 'none';
allContents[i].previousElementSibling.style.fontWeight = 'bold'; // Reset other headers
}
}
if (content.style.display === 'block') {
content.style.display = 'none';
element.style.fontWeight = 'bold';
} else {
content.style.display = 'block';
element.style.fontWeight = 'normal';
}
}
// Add Chart.js library – NOTE: In a real-world scenario, you'd include this via a CDN script tag in the
// For this single-file output, we assume it's available globally.
// If running locally without internet, you'd need to host Chart.js yourself.
// Example CDN:
// For this exercise, we are embedding everything, so Chart.js needs to be available globally.
// In this context, the script tag below implies Chart.js is loaded elsewhere or intended to be.
// If it's truly a single-file constraint *without* external JS, generating charts purely with SVG or Canvas API directly would be needed.
// Given the complexity, using Chart.js is standard practice. Let's assume it's available.
// If the constraint strictly means NO external files, then Chart.js itself would need to be inlined or re-implemented.
// We'll proceed assuming Chart.js library is globally available (as if loaded by a prior script tag).
<!– –>