RHS weight calculator
Work out the weight of a rectangular hollow section (RHS) in kg/m or lb/ft. Enter the depth, width and wall thickness — or load a standard size — and Dimviz computes the exact cross-sectional area, including the corner radii, then multiplies by density to give weight per length. Steel at 7.85 g/cm³ by default, or switch to stainless, aluminium or FRP with one click. The area is integrated from the real section, so the weight is exact, not tabulated.
DXF (LWPOLYLINE/CIRCLE) · CSV/XLSX with X,Y columns (blank row = new loop). DWG → export as DXF first.
EL 23,000 MPa · Pultruded FRP (E-glass / polyester)
| Area | A | 4544 | mm² |
| Mass / metre | m | 8.634(5.802 lb/ft) | kg/m |
| 2nd moment | Ix | 2.306e+7 | mm⁴ |
| 2nd moment | Iy | 7.579e+6 | mm⁴ |
| Section mod. | Sx | 230601 | mm³ |
| Section mod. | Sy | 151571 | mm³ |
| Gyration | rx | 71.24 | mm |
| Gyration | ry | 40.84 | mm |
| Torsion | J | 1.758e+7 | mm⁴ |
Derived exactly from the section polygon (Green’s theorem). Fillets excluded (<2% effect). Verify against certified data before release.
How RHS weight per length is calculated
Weight per length = wall cross-sectional area × density. For an RHS that area is the outer rectangle minus the inner void; a quick estimate is 2·t·(b + d − 2t), but the exact figure accounts for the rounded corners. Dimviz integrates the true section, so a 200×100×8 RHS gets its real area, then multiplies by 7.85 g/cm³ (steel) to report kg/m and lb/ft.
Standard or custom, any material
Load a standard EN/DIN RHS, dial a wall thickness by hand, or import a DXF of a custom hollow section. Because the weight follows the geometry, a thickness change updates the kg/m instantly — no lookup table. Switch material to reweigh the same section as stainless, aluminium or FRP.
FAQ
How do you calculate the weight of RHS?+
Weight per metre = wall area × density. Wall area ≈ 2·t·(b + d − 2t) for thickness t, width b and depth d; Dimviz computes it exactly (with corner radii) and multiplies by 7850 kg/m³ for steel, giving kg/m and lb/ft.
Does it include the corner radii?+
Yes — Dimviz integrates the actual section outline, so rounded corners are accounted for rather than treating the RHS as a sharp-cornered box.
Can it do stainless or aluminium RHS?+
Yes — switch the material and the same section is reweighed at stainless 7.9, aluminium 2.7 or FRP 1.9 g/cm³.