The Steel Plate / Bar Weight Calculator computes weight for rectangular plates, square / round / hex bars, hollow tubes, and channels using density 7,850 kg/m³ for mild steel. Useful for fabrication take-off, transport planning, and lifting / rigging calculations.
Switch units between mm/m/inch and kg/lb to match supplier conventions. The calculator also outputs surface area for paint / galvanizing estimates (m² per piece).
Mild steel: 7,850 kg/m³. Stainless steel grade 304: 8,000 kg/m³. SS grade 316: 8,000 kg/m³. Aluminium 6061: 2,700 kg/m³. Copper: 8,960 kg/m³. Brass: 8,500 kg/m³. The calculator defaults to mild steel; pick alternative materials from the dropdown for non-ferrous work.
Plate: L × W × T. Round bar: π × d² / 4 × L. Square bar: a² × L. Hex bar: 0.866 × s² × L (s = across-flat). Hollow round tube: π × (D² − d²) / 4 × L. Hollow square tube (HSS): (a² − (a − 2t)²) × L = (4at − 4t²) × L. The calculator handles each via dropdown selection.
Per IS 1730:1989 (rectangular plates) and IS 1786 (round bars), nominal vs actual weight tolerance is typically ±5% on plate thickness and ±3.5% on bar diameter. For lifting calculations, always design to the upper bound (nominal × 1.05) for safety. For material take-off / billing, use the nominal.
Per IS 1730:1989 Table 1: 5, 6, 8, 10, 12, 16, 20, 25, 32, 40, 50, 63, 80, 100 mm. Plates above 100 mm are special-order. For sheet (< 5mm thick), refer to IS 1079 (cold-rolled) or IS 513 (hot-rolled); availability in 0.5, 0.6, 0.8, 1.0, 1.6, 2.0, 2.5, 3.0, 4.0, 4.5 mm.
Same as rectangular plate but with area = π × d² / 4. For a 1m diameter, 10mm thick mild steel plate: V = π × 0.5² × 0.01 = 0.00785 m³. Weight = 0.00785 × 7,850 = 61.6 kg.
Three common reasons: (1) plate is over-tolerance — vendors often supply +0/+1.5 mm on thickness; (2) you're using a denser steel (e.g., HSS or alloy) — verify the spec; (3) galvanizing or coating adds ~3-7% to bare-steel weight. For accurate site measurement, weigh on a calibrated scale and back-calculate density.
Per IS terminology: thickness < 5 mm = sheet, ≥ 5 mm = plate. Sheets are typically cold-rolled (IS 513) or hot-rolled (IS 1079) and supplied in coils or flat blanks; plates are hot-rolled (IS 2062) and supplied in flat blanks only.