Steel Weight Calculator
Get a theoretical weight for common steel shapes — plate, flat bar, round and square bar, rectangular HSS, round pipe/tube and angle — in both metric and imperial units, before you order or quote a job.
How this is calculated
Weight = cross-sectional area × length × density. Each shape uses its own area formula: plate/flat bar = thickness × width; round bar = π × d² ÷ 4; square bar = side²; rectangular HSS = (w × h) − (w − 2t)(h − 2t); round pipe/tube = π/4 × (OD² − ID²); angle ≈ thickness × (leg A + leg B − thickness).
Density defaults to 7,850 kg/m³ for mild/carbon steel — edit it for stainless, aluminum or other alloys. This is a theoretical weight based on nominal dimensions; actual mill products vary within tolerance, so treat this as an estimate for planning and quoting, not a certified weight.
Frequently asked questions
Is this the exact weight I'll be charged for?
No — mills and suppliers apply manufacturing tolerances, and actual density can vary slightly by alloy and heat. Use this as a planning estimate, then confirm with your supplier's spec sheet for anything critical.
What density should I use for stainless or aluminum?
Stainless steel is typically around 7,900–8,000 kg/m³ and aluminum around 2,700 kg/m³. Edit the density field to match your material.
Why does rectangular HSS need a minimum thickness check?
The hollow-section formula subtracts an inner rectangle from the outer one. If wall thickness is too large relative to the outside dimensions, the inner rectangle becomes invalid — reduce thickness or increase width/height.
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