← Back to Bead BoardSteel round bar weight calculator
Mild steel round bar. 1018, A36, and every other hot-rolled round. Diameter in, length in, weight out. A 1 inch round 12 feet long is 32 pounds. A 2 inch round 20 feet long is 214 pounds. No guessing, no chart scrolling.
Weights are calculated from published densities and standard section geometry. Real plate and bar stock runs ±2–3% from spec.
Mild steel round bar weight per foot
Formula: π × (D/2)² × length × 0.2836. Real bar stock varies by a percent or two based on mill tolerance.
Questions welders ask about this one
How do you calculate round bar weight?
Multiply the cross-section area (π times the radius squared) by the length and by the density. For mild steel: π × (D/2)² × length × 0.2836 lb/in³. A 1 inch round bar 12 inches long = π × 0.25 × 12 × 0.2836 = 2.67 lb.
Is 1018 the same weight as A36 round bar?
Yes. 1018 and A36 have the same density to within any measurement you care about (0.2836 lb/in³). The difference is chemistry and mechanical properties, not weight.
Why does my 20 foot bar weigh less than the calculator says?
Mill tolerance. Hot-rolled bar can run 2–3% light from nominal diameter, especially on longer lengths. Cold-drawn and ground stock is closer to spec. If you are buying by the pound, check the supplier certification.
Other metal weight calculators
Steel Plate Weight
A36 mild steel plate. Every common thickness.
Steel Pipe Weight
NPS + Schedule 40/80/XXS, first principles.
Steel Square Tube (HSS)
Hollow structural section weight and wall thickness.
Aluminum Plate Weight
6061-T6 and 5052 plate, 4×8 and custom sizes.
Stainless Plate Weight
304 and 316 stainless plate, lb or kg.