SettingsSettings for this calculationUS
The tube's outer width.
For a square HSS, enter the same value as Outer Height.
The tube's outer height.
Outside face to outside face, the way HSS is designated — a 150 × 100 × 6 is 150 outside. The corners are radiused, typically to about twice the wall thickness, and that rounding removes steel a square-cornered calculation counts: a weight from nominal dimensions runs a few per cent heavy against the shape table, which is the conservative direction for a lift and the wrong one for a price.
The tube's nominal wall thickness.
The NOMINAL wall from the designation. The delivered wall is usually thinner — many HSS specifications permit a design thickness of about 93% of nominal for that reason, and shape tables are published on the design value. For weight, nominal is close enough; for a capacity check, use the design thickness, because the difference is 7% of the entire section.
Weight per unit length
12.76 lb/ft
- Cross-sectional area
- 3.75 in²
They open the calculator with your figures already in it
HSS (Square/Rectangular Tube) Weight Calculator: 12.76 lb/ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- HSS cross-sectional area = outer area − inner area = (width × height) − ((width − 2×wall thickness) × (height − 2×wall thickness)); weight per unit length = area × steel density (7850 kg/m³)
Inputs used
- Outer Width
- 4 in
- Outer Height
- 4 in
- Wall Thickness
- 0.25 in
Intermediate steps
- Cross-sectional area
- 3.75 in²
What this calculation does not cover
- The 7,850 kg/m³ (490 pcf) built into this is carbon steel and nothing else. The same outline in austenitic stainless is nearer 8,000 kg/m³ (499 pcf) and in aluminium about 2,700, so an aluminium section reads close to three times heavier here than it weighs. That gap matters most where the figure is feeding a lift plan, a temporary works check or a freight cost rather than a steel schedule.
- Weight is not a substitution rule. Two sections at the same mass per unit length can behave nothing alike — a deep thin-walled tube and a small thick-walled one of equal mass have very different second moments of area, section moduli and radii of gyration, and it is those, not the mass, that set deflection and buckling. Swapping in a section because it weighs about the same changes how the frame moves.
Add the equipment this sizes
This result is a specification — 12.76 lb/ft — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- HSS cross-sectional area = outer area − inner area = (width × height) − ((width − 2×wall thickness) × (height − 2×wall thickness)); weight per unit length = area × steel density (7850 kg/m³)
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