Steel Plate Weight Calculator
Mass per square metre, per plate and in total from size and thickness.
Inputs
Result
Formula
| Area | A = length (m) × width (m) |
| Mass per m² | W = thickness (mm) × 7.85 |
| Mass per plate | A × W |
| Total | per plate × quantity |
| Expanded | W = L × W × T × 7850 in metres |
| Plates per tonne | N = 1000 ÷ mass per plate |
2000 × 1000 × 10 mm, five plates: 2.000 m² each, 78.50 kg/m², 157.00 kg per plate, 785.00 kg total (0.785 t), about 6.37 plates to the tonne.
FAQ
Why does theoretical plate mass not match the scales?
Because the standard permits negative thickness tolerance — a 10 mm plate may be 9.2 mm, giving 72.2 kg/m² instead of 78.5, an 8% shortfall. Mills deliver on theoretical weight by trade custom, so the calculated total running high is expected; a deviation beyond tolerance means undersized plate, so check with a caliper on delivery.
How do I handle grating and checker plate?
Grating is not area times thickness — makers publish mass per square metre by specification (30 × 3 flat bar at 30 mm pitch is about 30 kg/m²), so use the table. Checker plate is the plain thickness times 1.05-1.08, the pattern being 0.5-1.0 mm high, which barely matters on large plates.
Why is thin sheet more penalised by theoretical weight?
Because tolerance is proportional: a 1 mm sheet permits ±0.1 mm, a 10% band, worse than the 8% on 10 mm plate. Thin sheet also covers more area per tonne, so errors accumulate. Colour-coated sheet at 0.5 mm should be 3.93 kg/m² but often measures 3.5 — the origin of the “thinner every year” complaint.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.