Metric Unit Calculator
The formula, your substituted values, and the evaluated result are shown below.
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View offerAffiliate link — we may earn a commission at no extra cost to you.Estimate steel weight from volume.
This is a planning estimate. Confirm dimensions, allowances, material specifications, applicable codes, and supplier requirements before purchasing or construction.
Estimate steel weight from volume.
Steel has a density of about 7,850 kg/m³, so its weight is simply its volume multiplied by that figure:
Weight (kg) = volume (m³) × 7,850
The only input is the steel's volume in cubic metres. Work that out from the shape first, as in the examples below.
Steel plate, 2.4 m × 1.2 m × 6 mm thick 1. Volume: 2.4 × 1.2 × 0.006 = 0.01728 m³ 2. Weight: 0.01728 × 7,850 = 135.6 kg
Round bar, 20 mm diameter, 6 m long 1. Cross-section: π × 0.01² = 0.000314 m² 2. Volume: 0.000314 × 6 = 0.001885 m³ 3. Weight: 0.001885 × 7,850 = 14.8 kg
| Shape | Volume |
|---|---|
| Plate or flat bar | length × width × thickness |
| Round bar | π × (diameter ÷ 2)² × length |
| Tube / pipe | π × (outer² − inner²) ÷ 4 × length |
| Square hollow section | (outer² − inner²) × length |
For standard structural sections like universal beams, channels and angles, use the manufacturer's mass per metre (kg/m) from its catalogue instead. It already accounts for the fillets and exact shape.
About 23.6 kg per m². A 2.4 × 1.2 m sheet weighs about 68 kg.
About 7,850 kg/m³ for carbon steel. Stainless steels are around 7,900–8,000 kg/m³.
Mass per metre ≈ diameter² ÷ 162 (diameter in mm), then multiply by the total length.