Metal weight calculator
Work out the weight per metre and the total weight of steel, stainless steel and aluminium tubes, bars, angles and sheet. Enter the size in millimetres; results update as you type.
Weight per metre
11.734 kg/m
Total weight
70.4 kg
Density: 7.85 kg/dm³
Steel square and rectangular tubes use the EN 10219 corner radii, the same as our size tables.
Formulas used
Weight per metre (kg/m) = cross-section area (mm²) × density (kg/dm³) ÷ 1000. The areas:
| Shape | Cross-section area (mm²) |
|---|---|
| Square tube | 4t (a − t) |
| Rectangular tube | 2t (h + b − 2t) |
| Round tube / pipe | π t (D − t) |
| Flat bar | w × t |
| Round bar | π d² / 4 |
| Square bar | a² |
| Hexagon bar | (√3 / 2) s² |
| Angle | t (a + b − t) |
| Sheet / plate | kg/m² = t × ρ |
Densities
Carbon steel 7.85 kg/dm³, stainless steel (AISI 304) 7.93 kg/dm³, aluminium 2.70 kg/dm³. Delivered weights can differ from calculated ones within the mass tolerance of the product standard.
For HEA, HEB, IPE and UPN beams see the steel beam size tables; for hollow sections see the hollow section tables.
Frequently asked questions
How do I calculate the weight of a steel square tube?
Multiply the cross-section area by the density of steel. For a 100×100×4 mm square tube to EN 10219 the area is 14.95 cm², so the weight is 14.95 × 7.85 ÷ 10 = 11.73 kg/m.
How much does a metre of steel round bar weigh?
Weight per metre = π/4 × d² × 7.85 ÷ 1000. A 50 mm round bar weighs π/4 × 50² × 7.85 ÷ 1000 ≈ 15.4 kg/m.
Why is aluminium lighter than steel for the same size?
Aluminium has a density of 2.70 kg/dm³ against 7.85 kg/dm³ for steel, so the same section weighs about a third as much.
How do I calculate the weight of a steel sheet?
Weight per m² = thickness (mm) × 7.85. A 2 mm sheet weighs 15.7 kg/m², so a 1250 × 2500 mm sheet weighs 15.7 × 1.25 × 2.5 ≈ 49.1 kg.