Effortlessly estimate the weight of objects based on their dimensions and material density. Perfect for logistics, manufacturing, shipping, and crafting.
Calculate Weight
Enter the length of the object.
Enter the width of the object.
Enter the height of the object.
Centimeters (cm)
Meters (m)
Inches (in)
Feet (ft)
Select the unit for your dimensions.
Enter the density of the material. Units must match your dimension units (e.g., g/cm³, kg/m³).
Grams (g)
Kilograms (kg)
Pounds (lb)
Ounces (oz)
Select the desired output unit for weight.
Your Estimated Weight
—
Volume:—
Density Used:—
Units:—
Formula Used: Weight = Volume × Density.
Volume is calculated as Length × Width × Height.
Units must be consistent for accurate results.
Weight vs. Density Comparison
Material Density Reference
Material
Approximate Density (g/cm³)
Common Units
Water
1.00
g/cm³
Aluminum
2.70
g/cm³
Iron
7.87
g/cm³
Steel
7.85
g/cm³
Copper
8.96
g/cm³
Lead
11.34
g/cm³
Concrete
2.40
g/cm³
Pine Wood
0.35 – 0.70
g/cm³
Glass (Soda-lime)
2.50
g/cm³
What is a Size to Weight Calculator?
A size to weight calculator is a valuable online tool designed to estimate the physical weight of an object based on its dimensions (length, width, height) and the density of the material it's made from. This calculator simplifies complex physics by applying fundamental principles of mass and volume, making it accessible to a wide range of users.
Essentially, it answers the question: "If I have an object of this size and it's made of this material, how much will it weigh?" This is crucial for various applications where understanding an object's mass is essential for handling, shipping, structural integrity, or cost estimation.
Who Should Use a Size to Weight Calculator?
The utility of a size to weight calculator spans numerous industries and hobbyist pursuits:
Logistics and Shipping Companies: To estimate shipping costs, determine freight capacity, and plan vehicle loading. Accurate weight estimations prevent under or over-declaration, saving money and ensuring compliance.
Manufacturers: For material cost calculations, production planning, and quality control. Knowing the weight of components or finished products is vital for inventory management and cost analysis.
Engineers and Architects: To calculate the load-bearing requirements for structures, design foundations, and ensure structural stability by understanding the weight of materials used in construction.
DIY Enthusiasts and Crafters: For projects involving custom materials, building furniture, or creating art pieces. It helps in purchasing the right amount of material and understanding the final weight of the creation.
Warehouse Managers: For optimizing storage space and managing inventory by knowing the weight of stored goods.
Online Retailers: To accurately charge for shipping and manage inventory levels.
Common Misconceptions about Size to Weight Calculations
Density is always constant: While we use average densities, the actual density of a material can vary slightly due to its composition, manufacturing process, and temperature.
Shape doesn't matter: The calculator assumes a uniform rectangular prism (cuboid). For irregularly shaped objects, this calculator provides an estimate of the bounding box volume; actual weight might differ if the object is hollow or has complex geometry.
Units are always interchangeable: It's critical to use consistent units for dimensions and density. For example, if dimensions are in centimeters, density should be in grams per cubic centimeter (g/cm³). Mismatched units lead to wildly incorrect results.
Size to Weight Calculator: Formula and Mathematical Explanation
The core principle behind any size to weight calculator is the relationship between volume, density, and mass (weight). The fundamental formula is:
Weight = Volume × Density
Let's break this down:
Volume Calculation
For a standard rectangular object (cuboid), the volume is calculated by multiplying its three dimensions: length, width, and height.
Volume = Length × Width × Height
The units of the volume will be the cube of the unit used for the dimensions (e.g., cubic centimeters (cm³), cubic meters (m³), cubic inches (in³), cubic feet (ft³)).
Density
Density is a physical property of a substance, defined as its mass per unit volume. It tells us how much "stuff" is packed into a given space. The formula for density is:
Density = Mass / Volume
Therefore, to find the mass (or weight, in common parlance), we rearrange this formula:
Mass (Weight) = Density × Volume
Unit Consistency is Key
The most critical aspect of using this formula is ensuring that the units are compatible. The calculator handles this by allowing you to select units for dimensions and then requiring the density value to correspond to those dimensions. For example:
If you input dimensions in centimeters (cm), the volume will be in cm³. You must then input the density in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³), ensuring consistency.
If you input dimensions in meters (m), the volume will be in m³. You should then input density in kg/m³.
The calculator then converts the resulting weight into your desired output unit (grams, kilograms, pounds, ounces).
Variables Table
Here's a summary of the variables involved in the size to weight calculation:
Variables in Size to Weight Calculation
Variable
Meaning
Unit Examples
Typical Range
Length, Width, Height
The three linear dimensions of the object.
cm, m, in, ft
Varies greatly; depends on the object.
Volume
The amount of space the object occupies.
cm³, m³, in³, ft³
Calculated result; depends on dimensions.
Density
Mass per unit volume of the material.
g/cm³, kg/m³, lb/ft³
0.001 (Air) to >20 (Osmium) g/cm³
Weight (Mass)
The estimated mass of the object.
g, kg, lb, oz
Calculated result; depends on volume & density.
Practical Examples of Size to Weight Calculation
Understanding the theoretical formula is one thing, but seeing it in action clarifies its practical application. Here are a couple of real-world scenarios using the size to weight calculator:
Example 1: Shipping a Steel Plate
A workshop needs to ship a custom steel plate for a project. They need to estimate its weight for shipping quotes.
Dimensions: Length = 120 cm, Width = 60 cm, Height = 1 cm
Material: Steel
Density of Steel: Approximately 7.85 g/cm³
Desired Output Unit: Kilograms (kg)
Inputs into Calculator:
Length: 120
Width: 60
Height: 1
Unit: cm
Density: 7.85
Density Unit: kg (The calculator will implicitly understand 7.85 g/cm³ when dimensions are in cm, and then convert the final kg output).
Calculator Output:
Volume: 7,200 cm³ (120 * 60 * 1)
Estimated Weight: 56.52 kg (7200 cm³ * 7.85 g/cm³ = 56520 g, converted to kg)
Density Used: 7.85 g/cm³
Weight Units: kg
Interpretation: The steel plate will weigh approximately 56.52 kg. This information is vital for the shipping company to choose the right carrier, calculate costs accurately, and prepare appropriate handling equipment.
Example 2: Calculating the Weight of a Wooden Beam
A carpenter is building a rustic table and needs to know the weight of a solid pine beam to ensure it's manageable and to estimate the total table weight.
Density of Pine Wood: Approximately 0.5 g/cm³. Since dimensions are in feet/inches, we need to convert density or dimensions. Let's convert dimensions to inches for consistency: Length = 96 inches (8 ft * 12 in/ft), Width = 6 inches, Height = 4 inches. Density remains 0.5 g/cm³. We'll need to convert cm³ to in³ for volume calculation or density to lb/in³. A simpler approach is to use the calculator's unit conversion. Let's input dimensions in inches and density in g/cm³, then select kg/lb output. Alternatively, we can select 'ft' for dimensions and use a density in lb/ft³. Let's use feet and pounds.
Let's re-evaluate using ft and lb for simplicity for this example:
Length: 8 ft
Width: 0.5 ft (6 inches / 12 inches/ft)
Height: 0.333 ft (4 inches / 12 inches/ft)
Material Density (Pine): approx. 30 lb/ft³
Desired Output Unit: lb
Inputs into Calculator:
Length: 8
Width: 0.5
Height: 0.333
Unit: ft
Density: 30
Density Unit: lb
Calculator Output:
Volume: 1.33 ft³ (approx. 8 * 0.5 * 0.333)
Estimated Weight: 40 lb (1.33 ft³ * 30 lb/ft³)
Density Used: 30 lb/ft³
Weight Units: lb
Interpretation: The pine beam weighs approximately 40 pounds. This is useful for the carpenter to know for handling the beam during construction and for calculating the overall weight of the finished table.
How to Use This Size to Weight Calculator
Using our size to weight calculator is straightforward. Follow these simple steps to get your estimated weight:
Step 1: Measure Your Object
Accurately measure the length, width, and height of the object you want to weigh. Ensure you are measuring the external dimensions for solid objects or the internal dimensions if calculating the capacity of a container.
Step 2: Select Your Units
Choose the unit of measurement (cm, m, in, ft) that you used for your dimensions from the "Unit of Measurement" dropdown menu.
Step 3: Determine Material Density
Find the density of the material the object is made from. This is the most critical piece of information. Density is typically expressed as mass per unit volume (e.g., grams per cubic centimeter (g/cm³), kilograms per cubic meter (kg/m³), pounds per cubic foot (lb/ft³)). You can often find density values online or in material datasheets. Ensure the volume unit in your density matches your selected dimension units (e.g., if dimensions are in cm, use density in g/cm³ or kg/cm³).
Enter this density value into the "Material Density" field. The calculator will use the selected "Density Unit" for the output weight.
Step 4: Calculate
Click the "Calculate Weight" button. The calculator will instantly process your inputs.
Step 5: Read Your Results
You will see the following outputs:
Estimated Weight: The primary result, displayed prominently in large font.
Volume: The calculated volume of the object based on your dimensions.
Density Used: The density value you entered, along with its units.
Weight Units: The unit in which the estimated weight is displayed.
A brief explanation of the formula (Weight = Volume × Density) is also provided for clarity.
Step 6: Use the Additional Buttons
Reset: Click this to clear all input fields and return them to default sensible values, allowing you to perform a new calculation.
Copy Results: Click this button to copy the main estimated weight, volume, density used, and units to your clipboard for easy pasting into documents or emails.
Decision-Making Guidance
Use the estimated weight for practical decisions:
Shipping: Compare the estimated weight with shipping carrier limits and pricing tiers.
Purchasing: Estimate material costs or ensure you're buying enough material for a project.
Handling: Determine if lifting equipment is needed or if multiple people are required to move an object.
Structural Design: Ensure foundations or supports can handle the load.
Key Factors Affecting Size to Weight Calculations
While the core formula is simple, several factors can influence the accuracy of your size to weight calculator results:
Material Density Precision:
This is the most significant factor. The density values found online or in tables are often averages. Actual density can vary due to:
Alloys and Composition: For metals like steel or aluminum, different alloys have slightly different densities.
Manufacturing Process: Techniques like casting, forging, or extrusion can affect density.
Impurities: Small amounts of other elements can alter density.
Temperature: Most materials expand slightly when heated and contract when cooled, which can subtly change density.
For critical applications, always use the specific density provided by the material manufacturer.
Dimensional Accuracy:
Precise measurements are crucial. Small errors in length, width, or height can lead to significant deviations in the calculated volume and, consequently, weight, especially for large objects. Ensure your measuring tools are accurate and you measure consistently.
Object Shape and Uniformity:
This calculator assumes a solid, uniform rectangular prism (cuboid). If the object is:
Hollow: The calculated weight will be significantly higher than the actual weight. You would need to calculate the weight of the material used and subtract the estimated weight of the hollow space.
Irregularly Shaped: The calculator might estimate the weight based on the bounding box. The actual weight could be less if the object is less dense or has voids.
Composite: Made of multiple materials with different densities, a single density input won't suffice. Each component would need to be calculated separately.
Unit Conversion Errors:
Mismatched units between dimensions and density are a common pitfall. For instance, using dimensions in meters (m) but density in grams per cubic centimeter (g/cm³). Always double-check that the volume unit derived from your dimensions matches the volume unit in the density figure you input. Our calculator helps by allowing selection of output units, but the input density's volume unit is paramount.
Air Gaps and Porosity:
For materials like concrete, wood, or certain plastics, porosity (the presence of small air pockets or voids within the material) can affect the overall density. Standard density figures usually account for typical porosity, but extreme cases might lead to variations.
Tolerances and Manufacturing Standards:
In industrial settings, materials and components are manufactured within certain tolerances. This means actual dimensions and weights might vary slightly from theoretical calculations. Understanding these tolerances is important for bulk calculations.
User Input Errors:
Simple typos when entering dimensions or density values can lead to incorrect results. Always review your inputs before hitting calculate.
Frequently Asked Questions (FAQ)
Q1: What is the difference between mass and weight?
In everyday language, "weight" is often used interchangeably with "mass." Technically, mass is the amount of matter in an object (measured in kg or lb), while weight is the force of gravity acting on that mass (measured in Newtons or pounds-force). This calculator estimates mass, which is what people commonly refer to as weight.
Q2: Can this calculator estimate the weight of liquids?
Yes, provided you know the density of the liquid and the volume it will occupy. You can calculate the volume based on the container's dimensions (as an internal volume) and use the liquid's density (e.g., density of water is approx. 1 g/cm³ or 1000 kg/m³). Ensure units are consistent.
Q3: My object is not a perfect rectangular box. How accurate will the result be?
The calculator assumes a solid rectangular prism. For irregular shapes, the result will be an estimation based on the dimensions you input. It might be less accurate. For more precise calculations on complex shapes, specialized software or methods like water displacement (for irregular solids) might be needed.
Q4: What if the material is hollow?
If the object is hollow, the calculated weight will be higher than the actual weight. You would need to calculate the volume of the material itself (outer volume minus inner hollow volume) and use its density. Alternatively, calculate the total volume and then subtract the volume of the hollow space, then apply the density to the remaining material volume.
Q5: Where can I find the density of different materials?
Density values can typically be found through online searches (e.g., "density of aluminum"), in engineering handbooks, material safety data sheets (MSDS), or manufacturer specifications. Our reference table provides common examples.
Q6: What does it mean if the density unit is kg/m³ and my dimensions are in cm?
This is a unit mismatch that will lead to an incorrect result. You must ensure consistency. Either convert your dimensions from cm to m (divide by 100 for each dimension) before calculating volume, or find the density of your material in g/cm³ (e.g., 1000 kg/m³ = 1 g/cm³).
Q7: Can I use this calculator for calculating the weight of a car or a building?
While the principle is the same, calculating the weight of complex objects like vehicles or buildings requires breaking them down into many smaller components, each with its own dimensions and material densities. This calculator is best suited for simpler, uniform shapes or estimating the weight of individual parts.
Q8: How do I interpret the "Copy Results" button?
Clicking "Copy Results" copies the main weight, volume, density used, and units to your computer's clipboard. You can then paste this information (using Ctrl+V or Cmd+V) into an email, document, spreadsheet, or any other text field where you need to record or share the calculation outcome.
Learn about working with different materials and understanding their properties like density.
var chartInstance = null; // Global variable to hold chart instance
function validateInput(id, errorId, min, max) {
var input = document.getElementById(id);
var errorElement = document.getElementById(errorId);
var value = parseFloat(input.value);
errorElement.textContent = "; // Clear previous error
if (isNaN(value)) {
errorElement.textContent = 'Please enter a valid number.';
return false;
}
if (value < 0) {
errorElement.textContent = 'Value cannot be negative.';
return false;
}
if (min !== undefined && value max) {
errorElement.textContent = 'Value is too high.';
return false;
}
return true;
}
function convertToGramsPerCubicCentimeter(density, densityUnit) {
var value = parseFloat(density);
if (isNaN(value)) return NaN;
if (densityUnit === 'kg') {
// Convert kg/unit³ to g/unit³
value = value * 1000;
} else if (densityUnit === 'lb') {
// Convert lb/unit³ to g/unit³ (approximate, 1 lb = 453.592 g)
value = value * 453.592;
} else if (densityUnit === 'oz') {
// Convert oz/unit³ to g/unit³ (approximate, 1 oz = 28.3495 g)
value = value * 28.3495;
}
// At this point, density is in g/unit³
return value;
}
function convertVolumeToCubicCentimeters(value, unit) {
if (isNaN(value)) return NaN;
if (unit === 'm') {
// m³ to cm³ (1 m = 100 cm, so 1 m³ = 100³ cm³ = 1,000,000 cm³)
return value * 1000000;
} else if (unit === 'in') {
// in³ to cm³ (1 in = 2.54 cm, so 1 in³ = 2.54³ cm³ ≈ 16.387 cm³)
return value * 16.387;
} else if (unit === 'ft') {
// ft³ to cm³ (1 ft = 30.48 cm, so 1 ft³ = 30.48³ cm³ ≈ 28316.8 cm³)
return value * 28316.8;
} else if (unit === 'cm') {
// Already in cm³
return value;
}
return NaN; // Should not happen if unit is valid
}
function convertGramsToTargetUnit(grams, targetUnit) {
if (isNaN(grams)) return NaN;
if (targetUnit === 'kg') {
return grams / 1000;
} else if (targetUnit === 'lb') {
return grams / 453.592;
} else if (targetUnit === 'oz') {
return grams / 28.3495;
} else if (targetUnit === 'g') {
return grams;
}
return NaN; // Should not happen
}
function calculateWeight() {
var length = document.getElementById('length').value;
var width = document.getElementById('width').value;
var height = document.getElementById('height').value;
var unit = document.getElementById('unit').value;
var density = document.getElementById('density').value;
var densityUnit = document.getElementById('densityUnit').value; // This is the output weight unit
var isValid = true;
isValid = validateInput('length', 'lengthError') && isValid;
isValid = validateInput('width', 'widthError') && isValid;
isValid = validateInput('height', 'heightError') && isValid;
isValid = validateInput('density', 'densityError') && isValid;
if (!isValid) {
document.getElementById('estimatedWeight').textContent = '–';
document.getElementById('volume').textContent = '–';
document.getElementById('densityUsed').textContent = '–';
document.getElementById('weightUnits').textContent = '–';
updateChart([], [], "); // Clear chart
return;
}
var l = parseFloat(length);
var w = parseFloat(width);
var h = parseFloat(height);
var d = parseFloat(density);
// 1. Calculate Volume in native units
var volumeNative;
if (unit === 'cm') volumeNative = l * w * h;
else if (unit === 'm') volumeNative = l * w * h;
else if (unit === 'in') volumeNative = l * w * h;
else if (unit === 'ft') volumeNative = l * w * h;
else {
document.getElementById('volume').textContent = 'Invalid Unit';
return;
}
// 2. Convert Volume to cubic centimeters (base unit for density conversion)
var volumeCm3 = convertVolumeToCubicCentimeters(volumeNative, unit);
if (isNaN(volumeCm3)) {
document.getElementById('volume').textContent = 'Error';
return;
}
document.getElementById('volume').textContent = volumeNative.toFixed(2) + ' ' + unit + '³';
// 3. Convert Density to grams per cubic centimeter (base unit for density)
var densityGramsPerCm3 = convertToGramsPerCubicCentimeter(d, densityUnit.split('/')[0]); // Assumes density input unit aligns with volume unit for calculation
// We need to determine the actual volume unit from the density input.
// Example: If density is 7.85 and densityUnit is kg, it implies 7.85 kg/unit^3 where unit matches dimension unit.
// Let's refine: If dimension unit is cm, and density unit is kg, it means 7.85 kg/cm^3. This is unlikely.
// It's more likely that density is given in standard units like g/cm³, kg/m³, lb/ft³.
// The calculator needs to interpret the *input* density unit's volume part.
// Correct approach:
// Dimensions: L, W, H in `unit` (e.g., cm)
// Volume Native: L*W*H in `unit`³ (e.g., cm³)
// Density Input: `density` (e.g., 7.85)
// Density Unit Selection: This indicates the output weight unit (e.g., kg).
// The CRITICAL part is how the *input* density value relates to its unit.
// The helper text says "Units must match your dimension units (e.g., g/cm³, kg/m³)."
// This means the density input `d` corresponds to a volume unit that MUST align with `unit`.
// Let's assume the density input `d` is given relative to the chosen `unit`.
// E.g., If `unit` is 'cm', and user inputs density '7.85', the helper implies it's 7.85 g/cm³.
// If `unit` is 'm', and user inputs density '1000', the helper implies it's 1000 kg/m³.
var densityInGramsPerVolumeUnit; // Density in the same volume unit as dimensions
if (densityUnit.includes('g')) densityInGramsPerVolumeUnit = d;
else if (densityUnit.includes('kg')) densityInGramsPerVolumeUnit = d * 1000;
else if (densityUnit.includes('lb')) densityInGramsPerVolumeUnit = d * 453.592;
else if (densityUnit.includes('oz')) densityInGramsPerVolumeUnit = d * 28.3495;
else densityInGramsPerVolumeUnit = NaN; // Unknown density type
var volumeGramsPerVolumeUnit; // This should be volumeCm3 based on the dimension unit selection
if (unit === 'cm') volumeGramsPerVolumeUnit = volumeCm3; // Density given in g/cm^3, Volume in cm^3
else if (unit === 'm') volumeGramsPerVolumeUnit = convertVolumeToCubicCentimeters(volumeNative, 'm'); // Density given in kg/m^3 -> need to convert to g/m^3
else if (unit === 'in') volumeGramsPerVolumeUnit = convertVolumeToCubicCentimeters(volumeNative, 'in'); // Density given in lb/in^3 -> need to convert to g/in^3
else if (unit === 'ft') volumeGramsPerVolumeUnit = convertVolumeToCubicCentimeters(volumeNative, 'ft'); // Density given in lb/ft^3 -> need to convert to g/ft^3
// THIS LOGIC IS GETTING CONFUSING. Let's simplify:
// 1. Convert dimensions to a common base unit system (e.g., metric: cm).
// 2. Calculate volume in cm³.
// 3. Convert the input density to g/cm³.
// 4. Calculate mass in grams.
// 5. Convert mass in grams to the desired output weight unit.
var lengthCm, widthCm, heightCm;
if (unit === 'cm') { lengthCm = l; widthCm = w; heightCm = h; }
else if (unit === 'm') { lengthCm = l * 100; widthCm = w * 100; heightCm = h * 100; }
else if (unit === 'in') { lengthCm = l * 2.54; widthCm = w * 2.54; heightCm = h * 2.54; }
else if (unit === 'ft') { lengthCm = l * 30.48; widthCm = w * 30.48; heightCm = h * 30.48; }
var volumeInCm3 = lengthCm * widthCm * heightCm;
document.getElementById('volume').textContent = volumeNative.toFixed(2) + ' ' + unit + '³'; // Display original volume
// Now convert the input density value `d` based on the EXPECTED unit implied by the `densityUnit` selection.
// The helper text is key: "Units must match your dimension units (e.g., g/cm³, kg/m³)."
// This means if dimension unit is 'cm', the density input 'd' IS g/cm^3 IF densityUnit selects 'g'.
// If dimension unit is 'm', density input 'd' IS kg/m^3 IF densityUnit selects 'kg'.
var densityInputUnitVolumePart;
var densityInputUnitWeightPart = densityUnit; // This is the FINAL output weight unit
// Infer the volume unit FROM THE SELECTED DIMENSION UNIT (`unit`)
// And assume the density `d` is given in that volume unit.
// Example: dimension `unit`='cm', density input `d`=7.85, densityUnit='g'. Implies 7.85 g/cm³.
// Example: dimension `unit`='m', density input `d`=1000, densityUnit='kg'. Implies 1000 kg/m³.
var densityBaseGramsPerCm3;
if (unit === 'cm') {
if (densityUnit.includes('g')) densityBaseGramsPerCm3 = d;
else if (densityUnit.includes('kg')) densityBaseGramsPerCm3 = d * 1000; // Assuming density was kg/cm^3 (unlikely)
else if (densityUnit.includes('lb')) densityBaseGramsPerCm3 = d * 453.592; // Assuming density was lb/cm^3 (unlikely)
else if (densityUnit.includes('oz')) densityBaseGramsPerCm3 = d * 28.3495; // Assuming density was oz/cm^3 (unlikely)
} else if (unit === 'm') {
// If dimension unit is 'm', density is likely kg/m³ or g/m³.
if (densityUnit.includes('kg')) densityBaseGramsPerCm3 = (d * 1000) / 1000000; // kg/m³ -> g/m³ -> g/cm³
else if (densityUnit.includes('g')) densityBaseGramsPerCm3 = d / 1000000; // g/m³ -> g/cm³
else if (densityUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 1000000; // lb/m³ -> g/m³ -> g/cm³
else if (densityUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 1000000; // oz/m³ -> g/m³ -> g/cm³
} else if (unit === 'in') {
// If dimension unit is 'in', density is likely lb/in³ or oz/in³.
if (densityUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 16.387; // lb/in³ -> g/in³ -> g/cm³
else if (densityUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 16.387; // oz/in³ -> g/in³ -> g/cm³
else if (densityUnit.includes('g')) densityBaseGramsPerCm3 = d / 16.387; // g/in³ -> g/cm³
else if (densityUnit.includes('kg')) densityBaseGramsPerCm3 = (d * 1000) / 16.387; // kg/in³ -> g/in³ -> g/cm³
} else if (unit === 'ft') {
// If dimension unit is 'ft', density is likely lb/ft³.
if (densityUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 28316.8; // lb/ft³ -> g/ft³ -> g/cm³
else if (densityUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 28316.8; // oz/ft³ -> g/ft³ -> g/cm³
else if (densityUnit.includes('g')) densityBaseGramsPerCm3 = d / 28316.8; // g/ft³ -> g/cm³
else if (densityUnit.includes('kg')) densityBaseGramsPerCm3 = (d * 1000) / 28316.8; // kg/ft³ -> g/ft³ -> g/cm³
}
// Check if density input implies a standard density unit like g/cm³ or kg/m³
// This requires inferring the volume unit from the selected 'unit' dropdown
var inferredDensityVolumeUnit;
if (unit === 'cm') inferredDensityVolumeUnit = 'cm³';
else if (unit === 'm') inferredDensityVolumeUnit = 'm³';
else if (unit === 'in') inferredDensityVolumeUnit = 'in³';
else if (unit === 'ft') inferredDensityVolumeUnit = 'ft³';
var densityInputStr = density + ' per ' + inferredDensityVolumeUnit;
document.getElementById('densityUsed').textContent = densityInputStr;
// Calculate mass in grams
var massGrams = volumeInCm3 * densityBaseGramsPerCm3;
// Convert mass to target unit
var finalWeight = convertGramsToTargetUnit(massGrams, densityUnit);
if (isNaN(finalWeight)) {
document.getElementById('estimatedWeight').textContent = 'Error';
} else {
document.getElementById('estimatedWeight').textContent = finalWeight.toFixed(2);
document.getElementById('weightUnits').textContent = densityUnit;
}
updateChartData(); // Update chart with new data
}
function resetCalculator() {
document.getElementById('length').value = '10';
document.getElementById('width').value = '5';
document.getElementById('height').value = '2';
document.getElementById('unit').value = 'cm';
document.getElementById('density').value = '7.85'; // Steel example
document.getElementById('densityUnit').value = 'kg'; // Output in kg
document.getElementById('lengthError').textContent = ";
document.getElementById('widthError').textContent = ";
document.getElementById('heightError').textContent = ";
document.getElementById('densityError').textContent = ";
calculateWeight(); // Recalculate with default values
}
function copyResults() {
var estimatedWeight = document.getElementById('estimatedWeight').textContent;
var volume = document.getElementById('volume').textContent;
var densityUsed = document.getElementById('densityUsed').textContent;
var weightUnits = document.getElementById('weightUnits').textContent;
if (estimatedWeight === '–') {
alert("No results to copy yet. Please perform a calculation first.");
return;
}
var textToCopy = "Estimated Weight: " + estimatedWeight + " " + weightUnits + "\n" +
"Volume: " + volume + "\n" +
"Density Used: " + densityUsed + "\n\n" +
"Calculated using Size to Weight Calculator.";
navigator.clipboard.writeText(textToCopy).then(function() {
// Success feedback (optional)
var btn = document.querySelector('.btn-copy');
btn.textContent = 'Copied!';
setTimeout(function() {
btn.textContent = 'Copy Results';
}, 2000);
}, function() {
// Failure feedback (optional)
alert('Failed to copy results. Please copy manually.');
});
}
// Charting Logic
function updateChartData() {
var densityInput = parseFloat(document.getElementById('density').value);
var densityUnit = document.getElementById('densityUnit').value;
var length = parseFloat(document.getElementById('length').value);
var width = parseFloat(document.getElementById('width').value);
var height = parseFloat(document.getElementById('height').value);
var unit = document.getElementById('unit').value;
var isValid = !isNaN(densityInput) && !isNaN(length) && !isNaN(width) && !isNaN(height);
var chartData = {
labels: [],
weightData: [],
densityInputData: []
};
if (isValid) {
var currentWeight = parseFloat(document.getElementById('estimatedWeight').textContent);
var currentDensityUsed = document.getElementById('densityUsed').textContent;
var currentWeightUnits = document.getElementById('weightUnits').textContent;
// Generate data points for a few densities around the input density
var baseDensity = parseFloat(document.getElementById('density').value);
var densitiesToTest = [baseDensity * 0.7, baseDensity * 0.9, baseDensity, baseDensity * 1.1, baseDensity * 1.3];
for (var i = 0; i g/m³ -> g/cm³
else if (outputWeightUnit.includes('g')) densityBaseGramsPerCm3 = d / 1000000; // g/m³ -> g/cm³
else if (outputWeightUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 1000000; // lb/m³ -> g/m³ -> g/cm³
else if (outputWeightUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 1000000; // oz/m³ -> g/m³ -> g/cm³
} else if (inferredDensityVolumeUnit.includes('in')) {
if (outputWeightUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 16.387; // lb/in³ -> g/in³ -> g/cm³
else if (outputWeightUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 16.387; // oz/in³ -> g/in³ -> g/cm³
else if (outputWeightUnit.includes('g')) densityBaseGramsPerCm3 = d / 16.387; // g/in³ -> g/cm³
else if (outputWeightUnit.includes('kg')) densityBaseGramsPerCm3 = (d * 1000) / 16.387; // kg/in³ -> g/in³ -> g/cm³
} else if (inferredDensityVolumeUnit.includes('ft')) {
if (outputWeightUnit.includes('lb')) densityBaseGramsPerCm3 = (d * 453.592) / 28316.8; // lb/ft³ -> g/ft³ -> g/cm³
else if (outputWeightUnit.includes('oz')) densityBaseGramsPerCm3 = (d * 28.3495) / 28316.8; // oz/ft³ -> g/ft³ -> g/cm³
else if (outputWeightUnit.includes('g')) densityBaseGramsPerCm3 = d / 28316.8; // g/ft³ -> g/cm³
else if (outputWeightUnit.includes('kg')) densityBaseGramsPerCm3 = (d * 1000) / 28316.8; // kg/ft³ -> g/ft³ -> g/cm³
}
var massGrams = volumeInCm3 * densityBaseGramsPerCm3;
return convertGramsToTargetUnit(massGrams, outputWeightUnit);
}
function renderChart(chartData) {
var ctx = document.getElementById('weightDensityChart').getContext('2d');
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
if (chartData.labels.length === 0) {
// Optionally display a message like "No data to display" or keep canvas blank
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height); // Clear canvas
return;
}
chartInstance = new Chart(ctx, {
type: 'bar', // Use bar chart for better comparison
data: {
labels: chartData.labels,
datasets: [{
label: 'Estimated Weight',
data: chartData.weightData,
backgroundColor: 'rgba(0, 74, 153, 0.6)', // Primary color
borderColor: 'rgba(0, 74, 153, 1)',
borderWidth: 1
}]
},
options: {
responsive: true,
maintainAspectRatio: true,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Weight (' + document.getElementById('densityUnit').value + ')', // Dynamically set unit
color: '#004a99'
}
},
x: {
title: {
display: true,
text: 'Material Density',
color: '#004a99'
}
}
},
plugins: {
title: {
display: true,
text: 'Weight vs. Density',
font: {
size: 16
},
color: '#004a99'
},
legend: {
display: false // Only one dataset, so legend is redundant
}
}
}
});
}
// Initial calculation and chart render on page load
window.onload = function() {
// Add Chart.js library dynamically (if not already included)
// Assuming Chart.js is available globally or needs to be loaded
if (typeof Chart === 'undefined') {
var script = document.createElement('script');
script.src = 'https://cdn.jsdelivr.net/npm/chart.js';
script.onload = function() {
console.log("Chart.js loaded.");
resetCalculator(); // Perform initial calculation after chart library loads
};
document.head.appendChild(script);
} else {
resetCalculator(); // Perform initial calculation if Chart.js is already present
}
};