Hollow Section Steel Weight Calculator
Accurately determine the weight of steel tubes (SHS, RHS, CHS) for your projects.
Rectangular Hollow Section (RHS)
Square Hollow Section (SHS)
Circular Hollow Section (CHS)
Select the shape of your steel hollow section.
Outer dimension for Square/Rectangular or Diameter for Circular.
Outer height for Rectangular sections. Not applicable for Square/Circular.
The thickness of the steel wall.
The total length of the steel section in meters.
Calculation Results
–.– kg
Cross-Sectional Area: –.– mm²
Volume: –.– m³
Weight Per Meter: –.– kg/m
The weight is calculated by multiplying the steel's volume by its density (assumed at 7850 kg/m³). Volume is derived from the cross-sectional area and length.
What is a Hollow Section Steel Weight Calculator?
A hollow section steel weight calculator is an online tool designed to quickly and accurately determine the mass of steel tubes used in construction, engineering, and fabrication. These tubes, often referred to as SHS (Square Hollow Sections), RHS (Rectangular Hollow Sections), or CHS (Circular Hollow Sections), are fundamental structural components. This calculator simplifies the complex geometrical calculations required to find the precise weight of a given length of steel tubing, considering its dimensions and wall thickness. It's an indispensable tool for anyone involved in material estimation, project budgeting, logistics, or structural design, helping to avoid under or over-ordering steel, which can lead to significant cost savings and improved project efficiency.
Who should use it: Structural engineers, architects, contractors, fabricators, steel merchants, procurement managers, DIY enthusiasts, and students learning about structural materials all benefit from using a hollow section steel weight calculator. Anyone who needs to estimate the weight of steel for transport, load calculations, or costings will find this tool invaluable.
Common misconceptions: A frequent misunderstanding is that all steel sections of similar outer dimensions weigh the same. In reality, the wall thickness plays a crucial role in determining the weight. Another misconception is that steel density is constant across all types of steel; while 7850 kg/m³ is a widely used standard, minor variations can exist. This calculator uses the standard density for accurate estimation.
Hollow Section Steel Weight Calculator Formula and Mathematical Explanation
The core principle behind calculating the weight of any material is its volume multiplied by its density. For hollow steel sections, this involves several steps:
1. Calculate the Cross-Sectional Area (A)
This is the area of the steel material itself, excluding the hollow interior. The formula varies based on the shape:
- For RHS (Rectangular Hollow Section):
$A = 2 \times (Outer Width + Outer Height) \times Wall Thickness – 4 \times Wall Thickness^2$
(Note: Subtracting $4 \times Wall Thickness^2$ corrects for the overlapping corners in a simple perimeter calculation.) - For SHS (Square Hollow Section):
$A = 4 \times Outer Side \times Wall Thickness – 4 \times Wall Thickness^2$
(Simplified: $A = P_{outer} \times t – 4t^2$, where $P_{outer}$ is the outer perimeter.) - For CHS (Circular Hollow Section):
$A = \pi \times (Outer Diameter – Wall Thickness) \times Wall Thickness$
(Simplified: $A = \pi \times (R_{outer}^2 – R_{inner}^2)$, where $R$ is the radius.)
2. Calculate the Volume (V)
Once the cross-sectional area is known, the volume is calculated by multiplying it by the length of the section.
$V = A \times Length$
Important: Ensure units are consistent. If Area is in mm² and Length is in meters, you need to convert Area to m² first.
$V (\text{m}^3) = A (\text{mm}^2) \times Length (\text{m}) / 1,000,000$
3. Calculate the Weight (W)
The final weight is the volume multiplied by the density of steel. The standard density of steel is approximately 7850 kg/m³.
$W = V \times Density$
$W (\text{kg}) = V (\text{m}^3) \times 7850 (\text{kg/m}^3)$
Variables Table
Here's a breakdown of the variables used in the hollow section steel weight calculation:
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| $D_{outer}$ / $W_{outer}$ / $H_{outer}$ | Outer Diameter / Width / Height | mm | 10 – 500+ |
| $t$ | Wall Thickness | mm | 0.5 – 20+ |
| $L$ | Length | m | 0.1 – 12+ |
| $A$ | Cross-Sectional Area | mm² | Varies greatly based on dimensions |
| $V$ | Volume | m³ | Calculated |
| $Density_{steel}$ | Density of Steel | kg/m³ | ~7850 (Standard) |
| $W$ | Total Weight | kg | Calculated |
| $W/m$ | Weight Per Meter | kg/m | Calculated |
Practical Examples (Real-World Use Cases)
Example 1: Structural Frame Beam (RHS)
A construction project requires rectangular hollow sections (RHS) for a supporting frame. The engineer specifies RHS with outer dimensions of 100mm width and 50mm height, a wall thickness of 5mm, and a length of 8 meters per beam.
- Inputs:
- Shape Type: RHS
- Outer Width: 100 mm
- Outer Height: 50 mm
- Wall Thickness: 5 mm
- Length: 8 m
- Calculation Steps:
- Area (A): $2 \times (100 + 50) \times 5 – 4 \times 5^2 = 2 \times 150 \times 5 – 4 \times 25 = 1500 – 100 = 1400$ mm²
- Volume (V): $1400 \, \text{mm}^2 \times 8 \, \text{m} / 1,000,000 = 0.0112$ m³
- Weight (W): $0.0112 \, \text{m}^3 \times 7850 \, \text{kg/m}^3 = 87.92$ kg
- Outputs:
- Weight Per Meter: $87.92 \, \text{kg} / 8 \, \text{m} \approx 10.99$ kg/m
- Total Weight: 87.92 kg
- Interpretation: Each 8-meter beam weighs approximately 87.92 kg. If 10 such beams are needed, the total steel weight required would be around 879.2 kg. This information is crucial for ordering the correct amount of steel and for calculating transportation weight limits. This detailed calculation demonstrates the importance of using a reliable [hollow section steel weight calculator](hollow-section-steel-weight-calculator).
Example 2: Balustrade Posts (SHS)
For a modern balcony balustrade, square hollow sections (SHS) are used as posts. The requirement is for 75mm x 75mm posts with a 3mm wall thickness, and each post is 1.2 meters tall.
- Inputs:
- Shape Type: SHS
- Outer Size: 75 mm
- Wall Thickness: 3 mm
- Length: 1.2 m
- Calculation Steps:
- Area (A): $4 \times 75 \times 3 – 4 \times 3^2 = 900 – 36 = 864$ mm²
- Volume (V): $864 \, \text{mm}^2 \times 1.2 \, \text{m} / 1,000,000 = 0.0010368$ m³
- Weight (W): $0.0010368 \, \text{m}^3 \times 7850 \, \text{kg/m}^3 = 8.139$ kg
- Outputs:
- Weight Per Meter: $8.139 \, \text{kg} / 1.2 \, \text{m} \approx 6.78$ kg/m
- Total Weight: 8.14 kg
- Interpretation: Each balustrade post weighs approximately 8.14 kg. If 20 posts are needed for the balcony, the total weight would be about 162.8 kg. This allows for accurate costing and ensures the structural integrity of the balustrade, highlighting the utility of a precise [steel tube weight calculator](steel-tube-weight-calculator).
How to Use This Hollow Section Steel Weight Calculator
Using this calculator is straightforward and requires just a few key measurements:
- Select Shape Type: Choose whether you are calculating for a Rectangular (RHS), Square (SHS), or Circular (CHS) hollow section using the dropdown menu.
- Enter Dimensions:
- For RHS: Input the outer width and outer height in millimeters (mm).
- For SHS: Input the outer side dimension (width = height) in millimeters (mm). The 'Outer Height' field will be automatically handled.
- For CHS: Input the outer diameter in millimeters (mm). The 'Outer Height' field is not applicable.
- Enter Wall Thickness: Input the thickness of the steel wall in millimeters (mm).
- Enter Length: Input the total length of the steel section in meters (m).
- Calculate: Click the "Calculate Weight" button.
How to read results: The calculator will display:
- Total Weight (kg): The primary result, showing the total mass of the steel section in kilograms.
- Cross-Sectional Area (mm²): The area of the steel material per unit length.
- Volume (m³): The total volume of the steel material.
- Weight Per Meter (kg/m): The weight of the steel section for every meter of its length.
Decision-making guidance: Use the results to verify supplier quotes, estimate shipping costs, plan lifting requirements, and ensure your structural designs are sound. The weight per meter is particularly useful for comparing different steel sections or grades.
Key Factors That Affect Hollow Section Steel Weight Results
While the calculator provides an accurate estimate based on provided inputs, several real-world factors can influence the actual weight:
- Steel Density Variations: Although 7850 kg/m³ is standard, different steel alloys can have slightly different densities. High-strength steels or specialized alloys might vary marginally.
- Manufacturing Tolerances: Steel sections are manufactured within specific tolerance limits for dimensions and wall thickness. Actual measurements might slightly deviate from nominal values, leading to minor weight differences. This is a common aspect of [steel fabrication](steel-fabrication) projects.
- Coating and Finishes: If the steel is galvanized, painted, or coated, this adds a small amount of weight. The calculator typically assumes bare steel unless a specific coating density is factored in.
- Corrosion/Rust: Over time, steel can corrode, adding surface material and increasing weight. Conversely, significant corrosion can lead to material loss.
- Complex Shapes or Welds: If the hollow section is part of a more complex assembly or has additional welded components, the total weight will increase beyond the simple calculation.
- Measurement Accuracy: The accuracy of the input measurements (outer dimensions, wall thickness, length) directly impacts the output. Precise measurements are key for reliable results.
- Temperature Effects: Steel expands and contracts with temperature. While the effect on density and dimensions is minimal for typical structural applications, it can be a consideration in extreme environments.
Frequently Asked Questions (FAQ)
Q1: What is the standard density of steel used in calculations?
A: The commonly accepted standard density for steel is 7850 kilograms per cubic meter (kg/m³). This value is used by most steel weight calculators, including this one.
Q2: Does the calculator account for the internal hollow space?
A: Yes, the calculation method inherently accounts for the hollow space by determining the cross-sectional area of the *steel material only* and then calculating its volume and weight.
Q3: Can I use this calculator for non-standard steel shapes?
A: This calculator is specifically designed for standard Rectangular (RHS), Square (SHS), and Circular (CHS) hollow sections. It may not provide accurate results for irregular or custom-formed sections.
Q4: What are the units expected for input?
A: Dimensions (width, height, diameter, wall thickness) should be entered in millimeters (mm), and the length should be entered in meters (m).
Q5: How accurate is the calculated weight?
A: The calculator provides a highly accurate theoretical weight based on the provided dimensions and standard steel density. Actual weights may vary slightly due to manufacturing tolerances and material variations.
Q6: What does "Weight Per Meter" mean?
A: "Weight Per Meter" (kg/m) indicates how much one linear meter of the specified steel section weighs. This is useful for comparing different profiles and for estimating weights when the total length is not precisely known or standardized.
Q7: How do I handle a steel section that is not exactly rectangular or square (e.g., slightly tapered)?
A: For significantly non-uniform shapes, you would need to calculate the average cross-sectional area or use specialized software. This calculator assumes consistent dimensions along the entire length.
Q8: Is the weight calculated for bare steel or coated steel?
A: The weight calculated is for bare steel. If the steel is coated (e.g., galvanized), the coating adds a small amount of weight, which is not included in this standard calculation. For precise inventory, consult the coating specifications.