Square Tube Weight Calculator

Compute the weight, cross‑sectional area, volume, and linear density of square and rectangular hollow sections. Select from common materials (steel, aluminum, copper, stainless) or enter a custom density.

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Total Weight = 0.00 lbs / 0.00 kg

Disclaimer: The weights shown in the metal weight calculator above are for reference only and should not form the basis of any calculation requiring precise or accurate information. For example, due to differences in manufacturing processes and alloy/material composition, it is not uncommon for theoretical weights and densities to differ significantly from actual weights and densities. Therefore, if an accurate weight calculation is required, you should obtain relevant, precise information from the manufacturer.

Understanding Square & Rectangular Tube Weight

The square tube weight calculator determines the mass of a hollow rectangular or square section based on its external dimensions, wall thickness, length, and material density. This is a fundamental calculation in structural engineering, mechanical design, and metal fabrication. Accurately estimating tube weight is essential for cost estimation, load analysis, transportation planning, and material selection.

Cross‑section area   A = W · H − (W − 2t) · (H − 2t)

Volume   V = A · L     Mass   m = ρ · V

where W = outer width, H = outer height, t = wall thickness, L = length, ρ = material density.

Why Use an Interactive Tube Weight Calculator?

  • Engineering precision: Quickly iterate over different sizes and wall thicknesses to find the optimal section for your structural or mechanical application.
  • Cost estimation: Accurately calculate material weight to estimate raw material costs and shipping expenses.
  • Design verification: Check whether a given tube section meets weight constraints for your project, from aircraft fuselages to building frames.
  • Educational value: Visualize how changing dimensions affects cross‑sectional area and weight, reinforcing concepts from mechanics of materials.

Derivation & Formula Deep Dive

The cross‑sectional area of a hollow rectangular section is the difference between the area of the outer rectangle and the inner rectangle. The outer area is W · H. The inner dimensions are reduced by twice the wall thickness on each side: inner width = W − 2t, inner height = H − 2t. Thus the inner area is (W − 2t)(H − 2t). The metal area is the difference:

A = W · H − (W − 2t)(H − 2t) = 2t(W + H − 2t)

This elegant simplification shows that the cross‑sectional area depends linearly on the wall thickness and the sum of the outer dimensions. For a square tube (W = H), the formula reduces to A = 4t(W − t). The volume is simply A multiplied by the length L. Finally, the mass is obtained by multiplying the volume by the material density ρ.

The linear density (mass per unit length) is ρ · A, which is particularly useful for structural design because it allows quick calculation of the weight of any length of tube without recomputing the area each time.

Step‑by‑Step Calculation Process

  1. Measure or specify the outer width W and outer height H of the tube (in mm).
  2. Specify the wall thickness t (in mm) and the total length L (in mm).
  3. Select a material from the presets (steel, aluminum, copper, etc.) or enter a custom density in kg/m³.
  4. The calculator computes the cross‑sectional area using A = W·H − (W−2t)(H−2t).
  5. Volume is computed as V = A · L (in mm³, then converted to cm³ or m³).
  6. Mass is computed as m = ρ · V (with unit conversions from mm³ to m³).
  7. Results are displayed in both metric (kg, kg/m) and imperial (lb, lb/ft) units.

Reference Table: Common Tube Sizes & Weights

The following values are calculated using the tool's formulas and are consistent with standard engineering handbooks (AISC, EN 10219).

Size (W×H×t) Material Area (mm²) Weight per meter (kg/m) Weight for 6 m (kg)
50×50×3 mm Steel (7850) 564 4.43 26.6
80×80×4 mm Steel (7850) 1216 9.55 57.3
100×100×5 mm Steel (7850) 1900 14.9 89.5
120×60×4 mm Steel (7850) 1376 10.8 64.8
60×60×3 mm Aluminum (2700) 684 1.85 11.1
50×50×2 mm Stainless (8000) 384 3.07 18.4
2″×2″×⅛″ (50.8×50.8×3.175) Steel (7850) 605 4.75 28.5
Case Study: Structural Steel Column Design

A structural engineer is designing a lightweight steel frame for a mezzanine floor. The columns will be fabricated from square hollow sections (SHS). Using this calculator, the engineer evaluates a 100×100×5 mm SHS steel tube (ρ = 7850 kg/m³). The calculator returns a cross‑sectional area of 1900 mm² and a weight of 14.9 kg/m. For a column height of 4.5 m, the total weight is 67.1 kg per column. With 12 columns, the total steel weight for columns alone is 805 kg. This information feeds into the foundation design, crane lifting plan, and cost estimate. The engineer can quickly test alternative sizes — for example, a 90×90×5 mm tube reduces weight to 13.1 kg/m, saving 10% in material cost while still meeting the load requirements.

Material Density & Its Influence

Density is a critical parameter. Steel (A36) has a density around 7850 kg/m³, while stainless steel (304) is slightly denser at 8000 kg/m³. Aluminum 6061 is about 2700 kg/m³ — roughly one‑third the weight of steel for the same volume. This makes aluminum attractive for aerospace, automotive, and portable structures. Copper (8900 kg/m³) and lead (11340 kg/m³) are significantly heavier and are used in specialized applications such as radiation shielding or ballast. The calculator's material presets make it easy to compare the weight of identical tube geometries across different materials.

Common Misconceptions & Pitfalls

  • "Square tube weight depends only on width and thickness." — False. The outer height also matters; for rectangular tubes, both W and H are needed.
  • "Thicker walls always mean heavier weight." — True, but the relationship is linear: A = 2t(W+H−2t), so increasing t adds material proportionally.
  • "Weight per meter is the same for all lengths." — The linear density (kg/m) is constant, so total weight scales linearly with length.
  • "Density is constant for all steel grades." — Slight variations exist (e.g., stainless 304 is ~8000 kg/m³ vs. carbon steel at ~7850 kg/m³). Use the correct value for precision.

Applications Across Industries

  • Construction: Steel square tubes are used for columns, beams, trusses, and handrails.
  • Automotive: Roll cages, chassis components, and suspension arms.
  • Aerospace: Lightweight aluminum tubes for fuselage and wing structures.
  • Furniture: Desks, chairs, and shelving systems.
  • Shipbuilding: Structural members and piping supports.

Rooted in engineering principles — This tool implements the fundamental equations of solid mechanics and material science as documented in standard references such as Roark's Formulas for Stress and Strain, the AISC Steel Construction Manual, and ASME Boiler and Pressure Vessel Code. The interactive visualization is built on HTML5 Canvas and has been verified against independent calculations. Reviewed by the GetZenQuery tech team, last updated July 2026.

Frequently Asked Questions

A square tube has equal outer width and height (W = H). A rectangular tube has different width and height (W ≠ H). The calculator supports both.

Use the unit toggle buttons below the input form. The calculator automatically converts results between kg and lb, and between kg/m and lb/ft. Inputs are always in mm for dimensions and kg/m³ for density.

No, this calculator is specifically for square and rectangular hollow sections. For circular tubes, please see our separate Pipe Weight Calculator.

The calculations use double‑precision floating‑point arithmetic. Results are accurate to better than 0.01% for typical dimensions. Minor deviations may occur due to rounding in displayed values.

This tool assumes sharp, square corners. For hot‑rolled or cold‑formed tubes with corner radii, the actual cross‑sectional area may be slightly larger. The difference is typically small (< 2%) for standard sections.

Refer to industry standards such as AISC Steel Construction Manual, EN 10219, or ASTM A500 / A513. Many manufacturers also publish dimensional and weight tables.
References: AISC Steel Construction Manual; Wikipedia: Hollow Structural Section; Engineering ToolBox.