Metal weight calculator
Work out the weight of any bar, tube, angle, channel or hollow section in steel, stainless steel, aluminium, copper or FRP. Pick a shape or a standard size, choose a material, and Dimviz multiplies the exact cross-sectional area by the material density to give weight per metre and per foot. Switch between metric and imperial with one click — the geometry is computed from the section, so the number 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 | 1136 | mm² |
| Mass / metre | m | 2.158(1.450 lb/ft) | kg/m |
| 2nd moment | Ix | 1.441e+6 | mm⁴ |
| 2nd moment | Iy | 473659 | mm⁴ |
| Section mod. | Sx | 28825 | mm³ |
| Section mod. | Sy | 18946 | mm³ |
| Gyration | rx | 35.62 | mm |
| Gyration | ry | 20.42 | mm |
| Torsion | J | 1.099e+6 | mm⁴ |
Derived exactly from the section polygon (Green’s theorem). Fillets excluded (<2% effect). Verify against certified data before release.
How metal weight per length is calculated
Weight per length is the simplest engineering identity there is: cross-sectional area × material density. Dimviz integrates the area straight from the section polygon (Green's theorem), so a 100×50×4 rectangular tube, an ⌀25 round bar or a 40×40 T-slot all get their true area, then multiply by the density you choose — steel 7.85, stainless 7.9, aluminium 2.7, copper 8.94 and FRP ≈1.9 g/cm³. Toggle to imperial and the same section is reported in lb/ft.
Standard sizes, or your own section
Load a standard EN/DIN metric size or a US customary size from the size chips, dial a dimension by hand, or import a DXF/CSV/Excel of a custom section. Because the weight follows the geometry, a wall thickness change or a bore updates the kg/m instantly — no lookup table to hunt through.
Why area × density beats a printed table
Printed weight tables assume nominal dimensions and a single density. Real sections have specific walls, fillets and bores, and you may be quoting a non-standard size. Computing from the actual geometry means the weight matches the part you're really making — and you can prove where the number came from.
FAQ
How do you calculate the weight of a metal bar?+
Weight per metre = cross-sectional area (m²) × density (kg/m³). For a round bar, area = π/4 × diameter². Dimviz computes the area from any shape automatically and multiplies by the material density you select, giving kg/m and lb/ft.
What is the density of steel, aluminium and copper?+
Structural steel ≈ 7850 kg/m³ (0.284 lb/in³), stainless 304 ≈ 7900, aluminium 6063 ≈ 2700 (0.098 lb/in³), copper ≈ 8940 (0.323 lb/in³) and pultruded FRP ≈ 1900 kg/m³.
Can it calculate weight in pounds per foot?+
Yes — switch the tool to imperial units and every section reports weight in lb/ft alongside the metric kg/m, computed from the same exact geometry.