Steel Weight Calculator
Weight of steel tubes, bars, plates and beams — instant results for all common grades
Steel is sold by weight, but cut and quoted by dimensions — which is why every fabricator, buyer, and engineer constantly converts between the two. This calculator computes the weight of any steel profile from its cross-section dimensions and length, using the exact density of the selected grade rather than a generic average.
Carbon steels (1020, 1045), alloy steels (4140, 4340), tool steel (D2), and spring steel (1095) are all included, with densities from 7,700 to 7,870 kg/m³. For quick estimates, the industry rule of thumb is 7,850 kg/m³ — a 1 m² steel plate 1 mm thick weighs 7.85 kg.
Typical uses: checking order weight before requesting a quote, planning transport (pallet and truck limits), estimating crane loads, and verifying supplier invoices that bill by theoretical weight.
Frequently Asked Questions
How do I calculate the weight of steel?
Multiply the cross-section area (m²) by length (m) and density (kg/m³). For example, a 40×40×3 mm square tube has an area of 444 mm² = 0.000444 m²; at 6 m length and 7,850 kg/m³ it weighs 0.000444 × 6 × 7850 ≈ 20.9 kg.
What is the weight of steel per m³?
Structural carbon steel weighs approximately 7,850 kg per cubic meter. Tool steels range down to about 7,700 kg/m³ and some alloy grades up to 7,870 kg/m³ — the calculator uses the exact density of the grade you select.
How much does a steel plate weigh?
Steel plate weight = length × width × thickness × density. A convenient shortcut: every 1 mm of thickness adds 7.85 kg per square meter. A standard 2000×1000×5 mm plate therefore weighs about 78.5 kg.
Is theoretical steel weight the same as actual weight?
Not exactly — rolling and wall-thickness tolerances (e.g. ±10% on welded tube walls per EN 10219) mean actual weight typically differs by 2–5%. Suppliers normally invoice by theoretical weight calculated from nominal dimensions, which is what this calculator gives you.