Metric Steel Weight Calculator
Professional estimation tool for engineering, construction, and logistics
Calculate Steel Weight & Cost
Select your shape, enter dimensions in millimeters (mm), and get instant weight results.
Carbon Steel (7850 kg/m³)
Stainless Steel 304 (7900 kg/m³)
Stainless Steel 316 (8000 kg/m³)
Aluminum (2700 kg/m³)
Cast Iron (7200 kg/m³)
Copper (8960 kg/m³)
Brass (8500 kg/m³)
Density affects the final weight calculation.
Plate / Sheet / Flat Bar
Round Bar / Rod
Square Bar
Round Tube / Pipe
Square Tube / Box Section
Angle Iron (Equal Leg)
Please enter a valid quantity.
Enter current market price to estimate costs.
Total Weight
0.00 kg
Weight Per Piece
0.00 kg
Total Metric Tonnes
0.000 t
Estimated Cost
0.00
| Parameter | Value |
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Material Weight Comparison (Equal Volume)
Comparison of your selected dimensions across common metals.
What is a Metric Steel Weight Calculator?
A metric steel weight calculator is an essential digital tool used by engineers, fabricators, architects, and logistics managers to estimate the mass of steel components based on their geometric dimensions. Unlike direct measurement, which requires the physical object to be present, this calculator uses the theoretical density of the material to provide accurate weight estimations during the planning, purchasing, and design phases.
Accurate weight calculation is critical for structural integrity analysis, determining shipping costs, selecting appropriate lifting equipment (cranes and forklifts), and estimating raw material costs. By inputting dimensions in millimeters (mm) and length in meters (m), professionals can instantly convert volume into mass using the standard density of steel.
While this tool is primarily designed for carbon steel, it is versatile enough to handle other metals like stainless steel, aluminum, and brass by adjusting the density factor, making it a universal tool for the metalworking industry.
Metric Steel Weight Formula and Mathematical Explanation
The core principle behind any metric steel weight calculator is the relationship between volume and density. The formula is straightforward:
Weight (kg) = Volume (m³) × Density (kg/m³)
However, since most engineering drawings specify cross-sectional dimensions in millimeters (mm) and lengths in meters (m), the formula requires unit conversion to ensure accuracy. The standard density used for Carbon Steel is 7850 kg/m³.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| L | Length of the piece | Meters (m) | 1m – 12m |
| W | Width | Millimeters (mm) | 10mm – 2000mm |
| T | Thickness | Millimeters (mm) | 1mm – 100mm |
| OD | Outer Diameter | Millimeters (mm) | 10mm – 500mm |
| ρ (rho) | Density | kg/m³ | 7850 (Steel) |
Shape-Specific Formulas
1. Steel Plate / Flat Bar:
Weight = (Length × Width × Thickness × 7850) / 1,000,000
(Note: Division by 1,000,000 converts mm² to m²)
2. Round Bar:
Weight = π × (Diameter/2)² × Length × Density / 1,000,000
3. Round Tube (Pipe):
Weight = π × ((OD/2)² – (ID/2)²) × Length × Density / 1,000,000
Where ID = OD – (2 × Wall Thickness)
Practical Examples (Real-World Use Cases)
Example 1: Estimating Steel Plates for a Floor Deck
Scenario: A construction manager needs to order steel plates for a mezzanine floor. The area requires 10 plates, each measuring 2 meters by 1 meter, with a thickness of 10mm.
- Input Shape: Plate
- Dimensions: Length = 2m, Width = 1000mm, Thickness = 10mm
- Quantity: 10 pieces
- Calculation:
- Volume per plate = 2 × 1.0 × 0.01 = 0.02 m³
- Weight per plate = 0.02 m³ × 7850 kg/m³ = 157 kg
- Total Weight = 157 kg × 10 = 1,570 kg (1.57 tonnes)
- Financial Impact: If steel costs $1.50/kg, the material cost is $2,355. Knowing the weight ensures the delivery truck is not overloaded.
Example 2: Structural Columns using Square Hollow Sections
Scenario: A fabricator is building a support frame using Square Hollow Sections (SHS). They need 4 columns, each 3 meters high. The profile is 100x100mm with a 5mm wall thickness.
- Input Shape: Square Tube
- Dimensions: Length = 3m, Width = 100mm, Thickness = 5mm
- Calculation:
- Outer Area = 100 × 100 = 10,000 mm²
- Inner Area = (100-10) × (100-10) = 8,100 mm²
- Steel Area = 1,900 mm² = 0.0019 m²
- Volume = 0.0019 m² × 3m = 0.0057 m³
- Weight per piece = 0.0057 × 7850 = 44.745 kg
- Total Weight = 178.98 kg
How to Use This Metric Steel Weight Calculator
- Select Material: Choose the metal type. The default is Carbon Steel (7850 kg/m³), but you can select Aluminum or Stainless Steel for different projects.
- Choose Shape: Select the profile that matches your item (e.g., Plate, Round Bar, Pipe).
- Enter Dimensions: Input the required dimensions. Note that cross-sectional dimensions (width, diameter) are in millimeters (mm), while length is in meters (m).
- Set Quantity: Enter the total number of pieces required.
- Review Cost (Optional): Enter the price per kg to get an estimated total material cost.
- Analyze Results: Use the "Total Weight" for logistics planning and "Estimated Cost" for budgeting.
Key Factors That Affect Metric Steel Weight Results
When using a metric steel weight calculator, several real-world factors can influence the final accuracy and financial implications:
- Rolling Tolerances: Steel mills produce materials within tolerance ranges. A "10mm" plate might actually be 10.3mm or 9.8mm, affecting the actual weight by ±5%.
- Material Density Variations: While 7850 kg/m³ is the standard for carbon steel, specific alloys may vary slightly. Stainless steel (grade 316) is denser (approx. 8000 kg/m³).
- Coating and Galvanizing: The calculator estimates bare metal weight. Galvanizing adds approximately 3-5% to the total weight due to the zinc layer.
- Corner Radii: For hollow sections and beams, the calculator uses geometric formulas. Real structural sections have rounded corners (radii) which slightly reduce the actual steel volume compared to a sharp-cornered theoretical model.
- Scrap and Waste: If you are cutting these pieces from larger stock lengths, the calculated weight is the finished weight. You must account for "kerf" (cutting width) and off-cut waste in your financial purchasing decisions.
- Logistics Costs: Weight directly impacts shipping. A calculation error that underestimates weight could push a shipment over the legal limit for a standard truck, requiring a specialized heavy haul permit.
Frequently Asked Questions (FAQ)
What is the standard density of steel in metric units?
The standard density used for commercial carbon steel is 7850 kg/m³ (kilograms per cubic meter) or 7.85 g/cm³.
Does this calculator account for the weight of welding or bolts?
No, this metric steel weight calculator computes the raw material weight of the main members only. You should add a contingency (typically 2-5%) for connections, welds, and bolts.
Why are dimensions in mm but length in meters?
This is the industry standard in construction and fabrication. Cross-sections require high precision (mm), while lengths are sold and measured in larger units (m).
How do I calculate the weight of Stainless Steel?
Select "Stainless Steel" from the material dropdown. Stainless steel is slightly heavier than carbon steel, typically around 7900-8000 kg/m³.
Can I calculate the weight of an I-Beam?
For I-beams, it is best to use standard tables because of the complex tapered flanges and fillets. However, you can approximate it by calculating the web and two flanges as three separate "Plate" calculations and adding them together.
What is the difference between Net Weight and Gross Weight?
Net weight is the weight of the finished part (calculated here). Gross weight includes the raw stock required to produce the part, including waste material cut away during fabrication.
How accurate is the cost estimation?
The cost is a raw material estimate only. It does not include labor, machining, shipping, or taxes. Always consult a supplier for a binding quote.
Is aluminum lighter than steel?
Yes, significantly. Aluminum has a density of approximately 2700 kg/m³, making it roughly one-third the weight of steel for the same volume.
Related Tools and Internal Resources
- Structural Analysis Tools – Analyze load-bearing capacities for your steel beams.
- Construction Cost Estimator – Comprehensive project budgeting beyond just materials.
- Material Density Chart – Reference densities for over 50 common engineering materials.
- Logistics Planning Guide – How to manage heavy freight and shipping limits.
- Metal Fabrication Costs – Understanding labor and processing fees in fabrication.
- Engineering Unit Converters – Convert between Imperial and Metric units instantly.
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}
// Main Calculation Logic
function calculateSteelWeight() {
// Get common inputs
var qty = parseFloat(document.getElementById('quantity').value) || 0;
var price = parseFloat(document.getElementById('pricePerKg').value) || 0;
var matSelect = document.getElementById('materialSelect');
density = parseFloat(matSelect.value);
var matName = matSelect.options[matSelect.selectedIndex].text;
// Validate Quantity
if (qty 0 && w > 0 && t > 0) {
// V = L * (W/1000) * (T/1000)
volumeM3 = l * (w / 1000) * (t / 1000);
} else isValid = false;
}
else if (currentShape === 'roundBar') {
var l = getVal('length');
var d = getVal('diameter');
if (l > 0 && d > 0) {
var r = (d / 1000) / 2;
volumeM3 = Math.PI * r * r * l;
} else isValid = false;
}
else if (currentShape === 'squareBar') {
var l = getVal('length');
var w = getVal('width');
if (l > 0 && w > 0) {
volumeM3 = (w / 1000) * (w / 1000) * l;
} else isValid = false;
}
else if (currentShape === 'roundTube') {
var l = getVal('length');
var od = getVal('outerDiameter');
var t = getVal('thickness');
if (l > 0 && od > 0 && t > 0 && t 0 && w > 0 && t > 0 && t 0 && w > 0 && t > 0 && t 0 ? formatCurrency(totalCost) : '—';
// Update Summary Table
updateSummaryTable(matName, qty, weightPerPiece, totalWeight, totalCost);
// Update Chart
drawChart(volumeM3);
}
function getVal(id) {
var el = document.getElementById(id);
if (!el) return 0;
var val = parseFloat(el.value);
if (isNaN(val) || val < 0) {
var err = document.getElementById('err-' + id);
if(err) err.style.display = 'block';
return 0;
}
var err = document.getElementById('err-' + id);
if(err) err.style.display = 'none';
return val;
}
function formatNum(num) {
return num.toLocaleString('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
}
function formatCurrency(num) {
return num.toLocaleString('en-US', { style: 'currency', currency: 'USD' });
}
function updateSummaryTable(mat, qty, unitW, totalW, cost) {
var tbody = document.getElementById('summaryTableBody');
var html = 'Invalid value
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