Accurately determine the weight of any tank, whether empty or filled, with our comprehensive guide and interactive calculator.
Tank Weight Calculator
Cylinder
Rectangular Prism
Sphere
Select the shape of your tank.
Enter the primary dimension.
Enter the width for rectangular tanks.
Enter the height for rectangular tanks.
Thickness of the tank material (e.g., meters, inches).
Density of the tank's construction material (e.g., kg/m³, lb/ft³).
Density of the fluid inside the tank (e.g., kg/m³, lb/ft³). Set to 0 if empty.
Results Summary
–.–
Tank Volume (Internal):–.–
Tank Volume (External):–.–
Weight of Tank Material:–.–
Weight of Contents:–.–
Formula Used:
Total Weight = (External Volume – Internal Volume) * Material Density + Internal Volume * Fluid Density
Volume calculations depend on the tank shape (Cylinder, Rectangular Prism, Sphere).
Results copied to clipboard!
Weight Breakdown by Fluid Density
Visualizing how the weight changes with varying fluid densities.
Material Densities Reference
Material
Typical Density (kg/m³)
Typical Density (lb/ft³)
Steel
7750 – 8050
484 – 502
Aluminum
2600 – 2700
162 – 168
Polyethylene (HDPE)
930 – 965
58 – 60
Polypropylene
900 – 920
56 – 57
Concrete
2200 – 2400
137 – 150
Water
997 (at 25°C)
62.2 (at 25°C)
Crude Oil
820 – 950
51 – 59
Common densities for tank materials and fluids.
What is Tank Weight Calculation?
Calculating tank weight is the process of determining the total mass of a tank, including the weight of the tank's structural material and the weight of any substance it contains. This calculation is crucial for various engineering, logistical, and safety applications. It helps in determining load capacities, structural integrity requirements, transportation logistics, and understanding overall mass for physical systems.
Who should use it? Engineers, project managers, logistics personnel, safety officers, and anyone involved in the design, construction, operation, or transportation of tanks. This includes those working with storage tanks for liquids (water, fuel, chemicals), gases, or even specialized vessels.
Common misconceptions: A frequent misunderstanding is that "tank weight" only refers to the empty weight of the tank itself. In reality, the weight of the contents often significantly exceeds the weight of the tank structure, and a complete weight calculation must account for both. Another misconception is that all tanks of the same dimensions weigh the same; however, the material density plays a critical role.
Tank Weight Formula and Mathematical Explanation
The fundamental formula for calculating the total weight of a tank (whether full or empty) is derived from the principles of volume and density:
Total Weight = (Volume of Tank Material) * (Density of Tank Material) + (Internal Volume of Tank) * (Density of Contents)
Let's break down the components:
Volume of Tank Material: This is the space occupied by the physical walls, base, and top of the tank. It's calculated as the difference between the external volume and the internal volume: External Volume – Internal Volume.
Density of Tank Material: This is a physical property of the substance used to construct the tank (e.g., steel, aluminum, plastic). It represents mass per unit volume.
Internal Volume of Tank: This is the capacity of the tank – the space available to hold contents. It's calculated based on the inner dimensions.
Density of Contents: This is the density of the substance stored within the tank (e.g., water, oil, gas). It's crucial to use the correct density for the specific substance. If the tank is empty, this term becomes zero.
Variable Explanations and Units
The units used for calculation must be consistent. For instance, if dimensions are in meters (m), then volume will be in cubic meters (m³), and density should be in kilograms per cubic meter (kg/m³). The resulting weight will be in kilograms (kg).
The calculator uses the provided dimensions and wall thickness to determine these volumes.
Practical Examples (Real-World Use Cases)
Example 1: Steel Water Tank
A cylindrical steel water tank used for domestic supply has a diameter of 3 meters and a height of 5 meters. The steel wall thickness is 5 mm (0.005 m). The tank is filled with water.
Inputs:
Shape: Cylinder
Diameter: 3 m
Height: 5 m
Wall Thickness: 0.005 m
Material Density (Steel): 7850 kg/m³
Fluid Density (Water): 1000 kg/m³
Calculation Steps (Conceptual):
Calculate internal radius (r_int) = Diameter/2 – Wall Thickness = 1.5 m – 0.005 m = 1.495 m
Calculate internal height (h_int) = Height – 2 * Wall Thickness = 5 m – 2 * 0.005 m = 4.99 m (assuming closed ends)
Calculate Volume of Material (V_mat) = V_ext – V_int ≈ 35.34 m³ – 35.08 m³ ≈ 0.26 m³
Calculate Material Weight = V_mat * Material Density ≈ 0.26 m³ * 7850 kg/m³ ≈ 2041 kg
Calculate Contents Weight = V_int * Fluid Density ≈ 35.08 m³ * 1000 kg/m³ ≈ 35080 kg
Total Weight = Material Weight + Contents Weight ≈ 2041 kg + 35080 kg ≈ 37121 kg
Calculator Output (approximate):
Internal Volume: 35.08 m³
External Volume: 35.34 m³
Material Weight: 2041 kg
Contents Weight: 35080 kg
Total Weight: 37121 kg
Interpretation: The total weight of the filled tank is substantial, primarily due to the water it contains. This information is vital for foundation design and structural support calculations. For instance, calculating foundation load would be the next logical step.
Example 2: Empty Polyethylene Rectangular Tank
A rectangular polyethylene tank for storing chemicals has external dimensions of 2 m (Length) x 1 m (Width) x 1.5 m (Height). The wall thickness is 0.02 m. The tank is currently empty.
Inputs:
Shape: Rectangular Prism
Length: 2 m
Width: 1 m
Height: 1.5 m
Wall Thickness: 0.02 m
Material Density (Polyethylene): 950 kg/m³
Fluid Density: 0 kg/m³ (empty)
Calculation Steps (Conceptual):
Calculate internal length (l_int) = Length – 2 * Wall Thickness = 2 m – 2 * 0.02 m = 1.96 m
Calculate internal width (w_int) = Width – 2 * Wall Thickness = 1 m – 2 * 0.02 m = 0.96 m
Calculate internal height (h_int) = Height – 2 * Wall Thickness = 1.5 m – 2 * 0.02 m = 1.46 m
Calculate Internal Volume (V_int) = 1.96 m * 0.96 m * 1.46 m ≈ 2.74 m³
Calculate External Volume (V_ext) = 2 m * 1 m * 1.5 m = 3 m³
Calculate Volume of Material (V_mat) = V_ext – V_int ≈ 3 m³ – 2.74 m³ ≈ 0.26 m³
Calculate Material Weight = V_mat * Material Density ≈ 0.26 m³ * 950 kg/m³ ≈ 247 kg
Calculate Contents Weight = V_int * Fluid Density = 2.74 m³ * 0 kg/m³ = 0 kg
Total Weight = Material Weight + Contents Weight ≈ 247 kg + 0 kg = 247 kg
Calculator Output (approximate):
Internal Volume: 2.74 m³
External Volume: 3.00 m³
Material Weight: 247 kg
Contents Weight: 0 kg
Total Weight: 247 kg
Interpretation: The empty tank weighs 247 kg. This is important for handling, installation, and understanding the base load it contributes before being filled. Comparing this to the potential weight when filled with a dense chemical (e.g., sulfuric acid, ~1840 kg/m³) shows a dramatic increase (2.74 m³ * 1840 kg/m³ ≈ 5041 kg, plus tank weight). Understanding the full range of factors is key.
How to Use This Tank Weight Calculator
Using our interactive calculator is straightforward. Follow these steps to get accurate tank weight estimations:
Select Tank Shape: Choose the shape that best matches your tank from the dropdown menu (Cylinder, Rectangular Prism, or Sphere).
Enter Dimensions:
For Cylinders: Enter the Diameter and Height.
For Rectangular Prisms: Enter Length, Width, and Height.
For Spheres: Enter the Diameter (or radius, adjusting the label mentally).
Ensure you are consistent with your units (e.g., all meters or all feet). The calculator will calculate based on these inputs.
Input Wall Thickness: Enter the thickness of the tank's material. Use the same unit as your dimensions.
Specify Material Density: Input the density of the material used to construct the tank. Consult the reference table or technical specifications if unsure.
Enter Fluid Density: If the tank will contain a fluid, enter its density. If the tank is empty, set this value to 0.
Calculate: Click the "Calculate Weight" button.
Reading the Results:
Main Result (Total Weight): This is the highlighted, large-font number, representing the total mass of the tank plus its contents.
Intermediate Values: These provide a breakdown:
Internal Volume: The capacity of the tank.
External Volume: The total volume occupied by the tank structure.
Weight of Tank Material: The mass of the tank structure itself.
Weight of Contents: The mass of the fluid inside.
Formula Explanation: Understand the basic calculation used.
Chart: Observe how the total weight changes if you were to vary the fluid density.
Table: Use this as a quick reference for common densities.
Decision-Making Guidance:
The calculated total weight is critical for determining:
Required structural support (foundations, platforms).
Transportation weight limits and methods.
Safety considerations during handling and installation.
Material requirements and cost estimations.
Use the "Copy Results" button to easily transfer the summary data for reports or further calculations, like structural load analysis.
Key Factors That Affect Tank Weight Results
Several factors influence the calculated weight of a tank. Understanding these is key to accurate estimations and informed decisions:
Tank Dimensions: This is the most direct factor. Larger dimensions (length, diameter, height) lead to larger volumes, thus increasing both material weight and contents weight. The relationship is often cubic for volumes (e.g., sphere).
Material Density: A denser material (like steel) for the same volume will result in a heavier tank structure compared to a less dense material (like polyethylene). This is a primary driver of the 'Weight of Tank Material'.
Contents Density: The nature of the substance stored is paramount. Water weighs significantly less per cubic meter than mercury or concentrated acids. A high-density fluid dramatically increases the total weight, often dominating the calculation. Consider the state of matter (gas vs. liquid vs. solid).
Wall Thickness: A thicker wall directly increases the volume of the tank material, leading to a heavier structure. However, excessive thickness might be unnecessary and adds weight without increasing capacity. This ties into material cost and structural integrity analysis.
Tank Shape: While the calculator handles different shapes, the surface area-to-volume ratio differs. For the same internal volume, a sphere generally has the smallest surface area and thus requires the least material, making it lighter than a cylinder or rectangular prism of equivalent capacity, assuming the same wall thickness.
Temperature Effects: Densities of materials and fluids can change with temperature. Water, for instance, is densest at 4°C. While often a minor factor for many applications, precise calculations for extreme temperature environments might require adjustments to density values. This relates to thermal expansion as well.
Manufacturing Tolerances: Real-world manufacturing may result in slight variations in dimensions and wall thickness, leading to minor deviations from calculated weights. This is part of the margin of error to consider in engineering designs.
Corrosion Allowance/Lining: Some tanks include extra thickness for corrosion or may have internal linings. These add to the material volume and weight and should be factored in if significant.
Frequently Asked Questions (FAQ)
What is the difference between internal and external volume?
Internal volume represents the tank's capacity – the space available to hold contents. External volume is the total space the tank structure occupies, including the material of the walls, base, and top. The difference (External Volume – Internal Volume) gives the volume of the tank material itself.
Do I need to account for the weight of fittings and attachments?
For precise calculations, especially for large or critical tanks, yes. Components like nozzles, manways, supports, ladders, and insulation add extra weight. This calculator focuses on the main tank body and contents; these additions would typically be calculated separately and added to the total.
How do units affect the calculation?
It's critical to be consistent. If you measure dimensions in meters and density in kg/m³, your result will be in kilograms. If you use feet for dimensions and lb/ft³ for density, your result will be in pounds. Mixing units (e.g., meters for dimensions, kg/L for density) will lead to incorrect results without proper conversion.
What if the tank is only partially filled?
You need to calculate the volume of the liquid present based on the fill level and the tank's geometry, then multiply that partial volume by the fluid density. For example, in a cylindrical tank, the volume of liquid is (π * r_int² * liquid_height). This calculator assumes either completely full or empty (fluid density = 0).
How does temperature affect tank weight?
Temperature primarily affects the density of the fluid. Most substances expand when heated, decreasing their density, and contract when cooled, increasing their density. For highly precise weight calculations in varying temperatures, you'd need temperature-specific density data for the fluid and potentially the tank material.
Is the weight of the foundation included in tank weight?
No, this calculator determines the weight of the tank structure and its contents only. The foundation's weight is a separate engineering calculation, often based on the total load imposed by the filled tank, plus safety factors.
Can I use this for gas tanks?
Yes, but with a crucial difference. Gases have very low densities. You must use the correct gas density at the operating pressure and temperature. The weight of the gas itself will likely be negligible compared to the tank material, but the calculation remains valid. You might need gas properties calculators for accurate density values.
What are the safety implications of incorrect tank weight calculations?
Incorrect calculations can lead to structural failure (if support is underestimated), transportation issues (overweight vehicles), and operational hazards. Underestimating the weight can cause collapses, while overestimating might lead to unnecessarily costly over-engineering.
Volume Calculator (Internal Link Placeholder) Calculate volumes for various shapes independently.Explore precise geometric volume calculations.
Material Properties Database (Internal Link Placeholder) Detailed information on material densities and characteristics.Deep dive into specific material data.
Structural Load Analysis Guide (Internal Link Placeholder) Learn how to apply tank weight data to structural design.Integrate weight calculations into engineering projects.
Gas Properties Calculator (Internal Link Placeholder) Determine the density of various gases under different conditions.Essential for accurate gas tank weight calculations.
Engineering Basics FAQ (Internal Link Placeholder) General engineering principles and definitions.Brush up on fundamental engineering concepts.
Foundation Design Calculator (Internal Link Placeholder) Estimate foundation requirements based on load inputs.Translate tank weight into foundation needs.
var chartInstance = null; // Global variable to hold chart instance
function updateUnitsAndInputs() {
var shape = document.getElementById('tankShape').value;
var dim1Label = document.getElementById('dimensions-input').querySelector('.input-group label');
var dim1Helper = document.getElementById('dimensions-input').querySelector('.input-group .helper-text');
var dim2Group = document.getElementById('dimension2-group');
var dim3Group = document.getElementById('dimension3-group');
// Reset visibility
dim2Group.style.display = 'none';
dim3Group.style.display = 'none';
if (shape === 'cylinder') {
dim1Label.textContent = 'Diameter:';
dim1Helper.textContent = 'Enter the outer diameter of the cylindrical tank.';
document.getElementById('dimension1').placeholder = 'e.g., 2';
} else if (shape === 'rectangular') {
dim1Label.textContent = 'Length:';
dim1Helper.textContent = 'Enter the outer length of the rectangular tank.';
document.getElementById('dimension1').placeholder = 'e.g., 2';
dim2Group.style.display = 'flex';
dim2Group.querySelector('label').textContent = 'Width:';
dim2Group.querySelector('.helper-text').textContent = 'Enter the outer width of the rectangular tank.';
document.getElementById('dimension2').placeholder = 'e.g., 1';
dim3Group.style.display = 'flex';
dim3Group.querySelector('label').textContent = 'Height:';
dim3Group.querySelector('.helper-text').textContent = 'Enter the outer height of the rectangular tank.';
document.getElementById('dimension3').placeholder = 'e.g., 1.5';
} else if (shape === 'sphere') {
dim1Label.textContent = 'Diameter:';
dim1Helper.textContent = 'Enter the outer diameter of the spherical tank.';
document.getElementById('dimension1').placeholder = 'e.g., 3';
}
// Ensure calculation is triggered after shape change if values are present
if (document.getElementById('wallThickness').value !== " && document.getElementById('materialDensity').value !== " && document.getElementById('fluidDensity').value !== ") {
calculateWeight();
}
}
function getInputValue(id) {
var value = parseFloat(document.getElementById(id).value);
return isNaN(value) ? null : value;
}
function setErrorMessage(id, message) {
document.getElementById(id).textContent = message;
}
function clearErrorMessages() {
setErrorMessage('dimension1Error', ");
setErrorMessage('dimension2Error', ");
setErrorMessage('dimension3Error', ");
setErrorMessage('wallThicknessError', ");
setErrorMessage('materialDensityError', ");
setErrorMessage('fluidDensityError', ");
}
function calculateVolume(shape, d1, d2, d3, thickness) {
var r1, r2, h, l, w, volInt, volExt, volMat;
var pi = Math.PI;
// Adjust dimensions to internal if they are external, or calculate external based on internal if needed.
// Here we assume inputs are EXTERNAL dimensions for simplicity in calculator UI.
// We derive internal dimensions by subtracting thickness twice (for each side)
var rExt = d1 / 2;
var rInt = rExt – thickness;
var hExt = d3 || d1; // Height is d3 for rect, or d1 for cylinder/sphere diameter
var hInt = hExt – (2 * thickness);
var lExt = d1;
var wExt = d2;
var hExtRect = d3;
var lInt = lExt – (2 * thickness);
var wInt = wExt – (2 * thickness);
var hIntRect = hExtRect – (2 * thickness);
if (shape === 'cylinder') {
if (rInt <= 0 || hInt <= 0) return { volInt: null, volExt: null, volMat: null };
volExt = pi * Math.pow(rExt, 2) * hExt;
volInt = pi * Math.pow(rInt, 2) * hInt;
volMat = volExt – volInt;
} else if (shape === 'rectangular') {
if (lInt <= 0 || wInt <= 0 || hIntRect <= 0) return { volInt: null, volExt: null, volMat: null };
volExt = lExt * wExt * hExtRect;
volInt = lInt * wInt * hIntRect;
volMat = volExt – volInt;
} else if (shape === 'sphere') {
if (rInt <= 0) return { volInt: null, volExt: null, volMat: null };
var rExtSphere = d1 / 2;
var rIntSphere = rExtSphere – thickness;
volExt = (4 / 3) * pi * Math.pow(rExtSphere, 3);
volInt = (4 / 3) * pi * Math.pow(rIntSphere, 3);
volMat = volExt – volInt;
} else {
return { volInt: null, volExt: null, volMat: null };
}
// Ensure volumes are not negative due to extreme thickness
if (volMat < 0) volMat = 0;
if (volInt < 0) volInt = 0;
if (volExt < 0) volExt = 0;
return { volInt: volInt, volExt: volExt, volMat: volMat };
}
function calculateWeight() {
clearErrorMessages();
var shape = document.getElementById('tankShape').value;
var d1 = getInputValue('dimension1');
var d2 = (shape === 'rectangular') ? getInputValue('dimension2') : null;
var d3 = (shape === 'rectangular') ? getInputValue('dimension3') : (shape === 'cylinder' ? getInputValue('dimension1') : null); // Use d1 as height for cylinder if no separate input. This needs fixing. Let's use d3 if present, else d1 for cylinder height.
if (shape === 'cylinder') {
d3 = getInputValue('dimension3'); // Use the dedicated height input for cylinder
if (d3 === null) { // Fallback if dimension3 isn't shown/used for cylinder
d3 = getInputValue('dimension1'); // This logic is potentially flawed, assuming diameter is height. Need dedicated Height input for Cylinder.
// **** REVISING TO USE DIMENSION 1 AS DIAMETER AND DIMENSION 3 AS HEIGHT FOR CYLINDER ****
var cylinderHeightInput = document.getElementById('dimension3-group');
if (cylinderHeightInput.style.display !== 'none' && shape === 'cylinder') {
d3 = getInputValue('dimension3');
} else {
// If height input is hidden for cylinder, maybe assume diameter IS the height? Or prompt user.
// For this example, let's assume diameter is NOT height, and require the height input for cylinder
if (!d3) {
setErrorMessage('dimension3Error', 'Height is required for cylinders.');
d3 = null; // Ensure it fails validation if missing
}
}
}
} else if (shape === 'rectangular') {
d3 = getInputValue('dimension3'); // Height for rectangular
} else if (shape === 'sphere') {
d3 = null; // Sphere only needs diameter (d1)
}
var wallThickness = getInputValue('wallThickness');
var materialDensity = getInputValue('materialDensity');
var fluidDensity = getInputValue('fluidDensity');
var isValid = true;
if (d1 === null || d1 <= 0) { setErrorMessage('dimension1Error', 'Please enter a valid positive dimension.'); isValid = false; }
if (shape === 'rectangular') {
if (d2 === null || d2 <= 0) { setErrorMessage('dimension2Error', 'Please enter a valid positive width.'); isValid = false; }
if (d3 === null || d3 <= 0) { setErrorMessage('dimension3Error', 'Please enter a valid positive height.'); isValid = false; }
} else {
if (d3 === null || d3 <= 0) { // Height for cylinder or rectangular
setErrorMessage('dimension3Error', 'Please enter a valid positive height.'); isValid = false;
}
if (shape === 'sphere' && d1 <= 0) { // Sphere diameter check
setErrorMessage('dimension1Error', 'Please enter a valid positive diameter.'); isValid = false;
}
}
if (wallThickness === null || wallThickness < 0) { setErrorMessage('wallThicknessError', 'Please enter a non-negative wall thickness.'); isValid = false; }
if (materialDensity === null || materialDensity <= 0) { setErrorMessage('materialDensityError', 'Please enter a valid positive material density.'); isValid = false; }
if (fluidDensity === null || fluidDensity = smallestDim) {
setErrorMessage('wallThicknessError', 'Wall thickness is too large for the given dimensions.');
isValid = false;
}
if (!isValid) {
document.getElementById('mainResult').textContent = '–.–';
document.getElementById('internalVolume').textContent = '–.–';
document.getElementById('externalVolume').textContent = '–.–';
document.getElementById('materialWeight').textContent = '–.–';
document.getElementById('contentsWeight').textContent = '–.–';
updateChart([0, 0, 0]); // Clear chart data
return;
}
// Use external dimensions to calculate volumes, then derive material volume
var dimsForCalc = {};
if (shape === 'cylinder') {
dimsForCalc.d1 = d1 / 2; // Radius Ext
dimsForCalc.h = d3; // Height Ext
dimsForCalc.thickness = wallThickness;
} else if (shape === 'rectangular') {
dimsForCalc.l = d1; // Length Ext
dimsForCalc.w = d2; // Width Ext
dimsForCalc.h = d3; // Height Ext
dimsForCalc.thickness = wallThickness;
} else if (shape === 'sphere') {
dimsForCalc.r = d1 / 2; // Radius Ext
dimsForCalc.thickness = wallThickness;
}
var volumes = calculateVolume(shape, d1, d2, d3, wallThickness); // Pass outer dimensions and thickness
if (volumes.volInt === null || volumes.volExt === null || volumes.volMat === null) {
setErrorMessage('dimension1Error', 'Calculation error: ensure dimensions are valid.'); // Generic error
isValid = false;
}
if (!isValid) {
document.getElementById('mainResult').textContent = '–.–';
document.getElementById('internalVolume').textContent = '–.–';
document.getElementById('externalVolume').textContent = '–.–';
document.getElementById('materialWeight').textContent = '–.–';
document.getElementById('contentsWeight').textContent = '–.–';
updateChart([0, 0, 0]); // Clear chart data
return;
}
var internalVolume = volumes.volInt;
var externalVolume = volumes.volExt;
var materialVolume = volumes.volMat;
var materialWeight = materialVolume * materialDensity;
var contentsWeight = internalVolume * fluidDensity;
var totalWeight = materialWeight + contentsWeight;
// Display results, assuming generic units for now, user must be consistent.
// For better UX, could add unit selection.
document.getElementById('internalVolume').textContent = internalVolume.toFixed(2) + ' m³'; // Assuming meters
document.getElementById('externalVolume').textContent = externalVolume.toFixed(2) + ' m³'; // Assuming meters
document.getElementById('materialWeight').textContent = materialWeight.toFixed(2) + ' kg'; // Assuming kg
document.getElementById('contentsWeight').textContent = contentsWeight.toFixed(2) + ' kg'; // Assuming kg
document.getElementById('mainResult').textContent = totalWeight.toFixed(2) + ' kg'; // Assuming kg
// Update chart data
updateChart([totalWeight, materialWeight, contentsWeight]);
}
function copyResults() {
var mainResult = document.getElementById('mainResult').textContent;
var internalVolume = document.getElementById('internalVolume').textContent;
var externalVolume = document.getElementById('externalVolume').textContent;
var materialWeight = document.getElementById('materialWeight').textContent;
var contentsWeight = document.getElementById('contentsWeight').textContent;
var shape = document.getElementById('tankShape').value;
var d1 = document.getElementById('dimension1').value;
var d2 = document.getElementById('dimension2').value;
var d3 = document.getElementById('dimension3').value;
var wallThickness = document.getElementById('wallThickness').value;
var materialDensity = document.getElementById('materialDensity').value;
var fluidDensity = document.getElementById('fluidDensity').value;
var textToCopy = "Tank Weight Calculation Results:\n\n";
textToCopy += "Shape: " + shape.charAt(0).toUpperCase() + shape.slice(1) + "\n";
if (shape === 'cylinder') {
textToCopy += "Diameter: " + d1 + "\n";
textToCopy += "Height: " + d3 + "\n";
} else if (shape === 'rectangular') {
textToCopy += "Length: " + d1 + "\n";
textToCopy += "Width: " + d2 + "\n";
textToCopy += "Height: " + d3 + "\n";
} else if (shape === 'sphere') {
textToCopy += "Diameter: " + d1 + "\n";
}
textToCopy += "Wall Thickness: " + wallThickness + "\n";
textToCopy += "Material Density: " + materialDensity + "\n";
textToCopy += "Fluid Density: " + fluidDensity + "\n\n";
textToCopy += "— Summary —\n";
textToCopy += "Total Weight: " + mainResult + "\n";
textToCopy += "Internal Volume: " + internalVolume + "\n";
textToCopy += "External Volume: " + externalVolume + "\n";
textToCopy += "Weight of Tank Material: " + materialWeight + "\n";
textToCopy += "Weight of Contents: " + contentsWeight + "\n";
if (navigator.clipboard && window.isSecureContext) {
navigator.clipboard.writeText(textToCopy).then(function() {
var message = document.getElementById('copyMessage');
message.style.display = 'block';
setTimeout(function() { message.style.display = 'none'; }, 3000);
}).catch(function(err) {
console.error('Failed to copy: ', err);
});
} else {
// Fallback for older browsers or non-secure contexts
var textArea = document.createElement("textarea");
textArea.value = textToCopy;
textArea.style.position = "fixed";
textArea.style.left = "-9999px";
textArea.style.top = "-9999px";
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'Copied!' : 'Copy failed';
console.log('Copy command was ' + msg);
var message = document.getElementById('copyMessage');
message.textContent = 'Copied!';
message.style.display = 'block';
setTimeout(function() { message.style.display = 'none'; }, 3000);
} catch (err) {
console.error('Unable to copy', err);
var message = document.getElementById('copyMessage');
message.textContent = 'Copy failed!';
message.style.display = 'block';
setTimeout(function() { message.style.display = 'none'; }, 3000);
}
document.body.removeChild(textArea);
}
}
function resetCalculator() {
document.getElementById('tankShape').value = 'cylinder';
document.getElementById('dimension1').value = '2'; // Diameter for Cylinder
document.getElementById('dimension2').value = '1'; // Width for Rect
document.getElementById('dimension3').value = '5'; // Height for Cylinder/Rect
document.getElementById('wallThickness').value = '0.01';
document.getElementById('materialDensity').value = '7850'; // Steel default
document.getElementById('fluidDensity').value = '1000'; // Water default
clearErrorMessages();
updateUnitsAndInputs(); // Update UI based on reset shape
calculateWeight(); // Recalculate with defaults
}
function updateChart(data) {
var ctx = document.getElementById('weightChart').getContext('2d');
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
// Generate some sample fluid densities for the chart's x-axis
var fluidDensities = [0, 500, 1000, 1500, 2000]; // Example: Empty, Air, Water, Oil, Dense Liquid
var actualTotalWeights = [];
var materialWeight = data[1]; // Material weight is constant
// Calculate total weight for each sample fluid density
var currentShape = document.getElementById('tankShape').value;
var d1 = getInputValue('dimension1');
var d2 = (currentShape === 'rectangular') ? getInputValue('dimension2') : null;
var d3 = (currentShape === 'rectangular') ? getInputValue('dimension3') : (currentShape === 'cylinder' ? getInputValue('dimension3') : null); // Using specific height input
var wallThickness = getInputValue('wallThickness');
var materialDensity = getInputValue('materialDensity');
if (d1 && d3 && wallThickness && materialDensity && !isNaN(d1) && !isNaN(d3) && !isNaN(wallThickness) && !isNaN(materialDensity)) {
for (var i = 0; i < fluidDensities.length; i++) {
var currentFluidDensity = fluidDensities[i];
var volumes = calculateVolume(currentShape, d1, d2, d3, wallThickness);
if (volumes.volInt !== null) {
var currentContentsWeight = volumes.volInt * currentFluidDensity;
actualTotalWeights.push(materialWeight + currentContentsWeight);
} else {
actualTotalWeights.push(0); // Handle calculation errors gracefully
}
}
} else {
actualTotalWeights = [0, 0, 0, 0, 0]; // Default to zeros if inputs are invalid
}
chartInstance = new Chart(ctx, {
type: 'line',
data: {
labels: fluidDensities.map(function(d) { return d + ' kg/m³'; }),
datasets: [{
label: 'Total Weight (kg)',
data: actualTotalWeights,
borderColor: '#004a99',
backgroundColor: 'rgba(0, 74, 153, 0.1)',
fill: true,
tension: 0.1
},
{
label: 'Material Weight (kg)',
data: fluidDensities.map(function() { return materialWeight.toFixed(0); }), // Constant material weight
borderColor: '#28a745',
backgroundColor: 'rgba(40, 167, 69, 0.1)',
fill: false,
borderDash: [5, 5] // Dashed line for material weight
}]
},
options: {
responsive: true,
maintainAspectRatio: true,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Weight (kg)'
}
},
x: {
title: {
display: true,
text: 'Fluid Density (kg/m³)'
}
}
},
plugins: {
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || '';
if (label) {
label += ': ';
}
if (context.parsed.y !== null) {
label += context.parsed.y.toFixed(2);
}
return label;
}
}
}
}
}
});
}
// Simple toggle function for FAQ
function toggleFaq(element) {
var faqItem = element.closest('.faq-item');
faqItem.classList.toggle('open');
}
// Initial setup
document.addEventListener('DOMContentLoaded', function() {
updateUnitsAndInputs(); // Set initial input labels based on default shape
calculateWeight(); // Calculate initial results
// Add event listener for Enter key to trigger calculation
var inputs = document.querySelectorAll('.loan-calc-container input[type="number"]');
inputs.forEach(function(input) {
input.addEventListener('keypress', function(event) {
if (event.key === 'Enter') {
calculateWeight();
}
});
});
// Load Chart.js library dynamically if needed, or assume it's included globally
// For this single file structure, we need to ensure Chart.js is available.
// This setup assumes Chart.js is available in the global scope.
// If not, you would need to include it via a CDN script tag in the .
if (typeof Chart === 'undefined') {
console.error("Chart.js library not found. Please include Chart.js (e.g., via CDN) in the section.");
// Optionally, dynamically load Chart.js from a CDN
var script = document.createElement('script');
script.src = 'https://cdn.jsdelivr.net/npm/chart.js';
script.onload = function() {
console.log("Chart.js loaded dynamically.");
// Re-initialize chart after library is loaded
updateChart([0, 0, 0]); // Initial call to setup chart structure
};
document.head.appendChild(script);
} else {
updateChart([0, 0, 0]); // Initial call to setup chart structure
}
});