function toggleFields() {
var shape = document.getElementById("tubeShape").value;
var labelDim1 = document.getElementById("labelDim1");
var groupDim2 = document.getElementById("groupDim2");
var inputDim2 = document.getElementById("dimension2");
if (shape === "round") {
labelDim1.innerHTML = "Outer Diameter (OD)";
groupDim2.style.display = "none";
inputDim2.value = ""; // Clear value
} else if (shape === "square") {
labelDim1.innerHTML = "Side Width";
groupDim2.style.display = "none";
inputDim2.value = ""; // Clear value
} else if (shape === "rectangular") {
labelDim1.innerHTML = "Width (Side 1)";
groupDim2.style.display = "flex";
}
// Hide results when type changes to encourage recalculation
document.getElementById("resultBox").style.display = "none";
document.getElementById("calcWarning").style.display = "none";
}
function calculateTubeWeight() {
// Inputs
var shape = document.getElementById("tubeShape").value;
var d1 = parseFloat(document.getElementById("dimension1").value);
var wall = parseFloat(document.getElementById("wallThickness").value);
var length = parseFloat(document.getElementById("tubeLength").value);
var d2 = parseFloat(document.getElementById("dimension2").value);
// Elements
var warningEl = document.getElementById("calcWarning");
var resultBox = document.getElementById("resultBox");
var wpfEl = document.getElementById("weightPerFoot");
var totalEl = document.getElementById("totalWeight");
var lenDisplay = document.getElementById("totalLenDisplay");
// Reset
warningEl.style.display = "none";
warningEl.innerHTML = "";
resultBox.style.display = "none";
// Validation
if (isNaN(d1) || d1 <= 0) {
warningEl.innerHTML = "Please enter a valid Outer Dimension.";
warningEl.style.display = "block";
return;
}
if (isNaN(wall) || wall <= 0) {
warningEl.innerHTML = "Please enter a valid Wall Thickness.";
warningEl.style.display = "block";
return;
}
if (isNaN(length) || length 0 for totals
}
// Logical validation (Wall too thick)
if (wall * 2 >= d1) {
warningEl.innerHTML = "Wall thickness cannot be equal to or greater than half the diameter/width.";
warningEl.style.display = "block";
return;
}
if (shape === "rectangular") {
if (isNaN(d2) || d2 = d2) {
warningEl.innerHTML = "Wall thickness cannot be equal to or greater than half the height.";
warningEl.style.display = "block";
return;
}
}
// Calculation Constants
var density = 0.2833; // lbs per cubic inch for Carbon Steel
// Calculate Area (Square Inches)
var area = 0;
if (shape === "round") {
// Area = PI * (R_out^2 – R_in^2)
// R_out = d1 / 2
// R_in = (d1 – 2*wall) / 2
var r_out = d1 / 2;
var r_in = (d1 – (2 * wall)) / 2;
area = Math.PI * ((r_out * r_out) – (r_in * r_in));
} else if (shape === "square") {
// Area = OuterArea – InnerArea
var innerSide = d1 – (2 * wall);
area = (d1 * d1) – (innerSide * innerSide);
} else if (shape === "rectangular") {
// Area = (W*H) – ((W-2t)*(H-2t))
var innerW = d1 – (2 * wall);
var innerH = d2 – (2 * wall);
area = (d1 * d2) – (innerW * innerH);
}
// Calculate Weight
// Weight per foot = Area (sq in) * 12 (in/ft) * Density (lbs/in^3)
var weightPerFt = area * 12 * density;
var totalWeight = weightPerFt * length;
// Display Results
wpfEl.innerHTML = weightPerFt.toFixed(3) + " lbs/ft";
totalEl.innerHTML = totalWeight.toFixed(2) + " lbs";
lenDisplay.innerHTML = length;
resultBox.style.display = "block";
}
// Initialize state
toggleFields();
How to Calculate Steel Tubing Weight
Calculating the weight of steel tubing is a critical step in structural engineering, fabrication estimating, and shipping logistics. Unlike solid bars, tubing is hollow, meaning the calculation requires determining the volume of the material in the tube's wall and multiplying it by the density of steel.
The standard density for carbon steel used in most calculations is 0.2833 lbs/in³ (pounds per cubic inch) or approximately 490 lbs/ft³. This calculator uses the dimensional inputs to find the cross-sectional area of the steel profile and extrapolates that over a one-foot length.
Formulas by Shape
The logic behind the calculator depends on the geometric shape of the tubing:
1. Round Tubing (Pipe)
Round tubing weight is determined by subtracting the area of the inner circle from the outer circle. The simplified industry formula often used is:
Wall Thickness: Thickness of the tube wall in inches.
2. Square Tubing (HSS)
For square hollow structural sections (HSS), the formula calculates the volume of the four walls. While exact calculations account for the corner radius (curvature), a standard theoretical calculation (treating corners as square) is:
Once the area is found, it is multiplied by 12 inches and the material density.
Why Weight Calculation Matters
Cost Estimation: Steel is often sold by weight. Knowing the total lbs/ft helps in estimating material costs accurately.
Structural Load: Engineers must account for the self-weight of the tubing when designing frames, trusses, or supports.
Shipping & Handling: Calculating the total weight of a bundle ensures that trucks and forklifts are not overloaded.
Common Wall Thicknesses
When measuring steel tubing, wall thickness is often expressed in Gauge (ga) for thinner tubes or fractions of an inch for structural members. Here are common conversions:
16 Gauge: ~0.065 inches
14 Gauge: ~0.083 inches
11 Gauge: ~0.120 inches
3/16 inch: 0.188 inches
1/4 inch: 0.250 inches
This calculator provides theoretical weights based on nominal dimensions. Actual manufacturing tolerances may result in slight variations in the physical product.