Metal Weight Calculator & Weights Reference (UK)
Metal Weight Calculator & Weights Reference (UK)
Work out the weight of steel, stainless steel and aluminium — sheet & plate, box section, angle, flat and round bar, and tube. Use the calculator for any size, or the reference tables below for common ones.
Metal densities
| Material | Density (kg/m³) | Weight of 1mm sheet (kg/m²) |
|---|---|---|
| Mild / carbon steel (S275, CR4) | 7,850 | 7.85 |
| Galvanised steel (DX51D) | ~7,850 | ~7.85 (+ zinc coat) |
| Stainless steel 304 / 316 | 8,000 | 8.00 |
| Aluminium (1050 / 5754 / 6063) | 2,700 | 2.70 |
Sheet & plate weight per m²
Multiply by your sheet area to get the full-sheet weight. Weight per m² = thickness (mm) × density factor above.
| Thickness | Mild steel (kg/m²) | Stainless (kg/m²) | Aluminium (kg/m²) |
|---|---|---|---|
| 0.8 mm | 6.28 | 6.40 | 2.16 |
| 1.0 mm | 7.85 | 8.00 | 2.70 |
| 1.5 mm | 11.78 | 12.00 | 4.05 |
| 2.0 mm | 15.70 | 16.00 | 5.40 |
| 3.0 mm | 23.55 | 24.00 | 8.10 |
| 4.0 mm | 31.40 | 32.00 | 10.80 |
| 5.0 mm | 39.25 | 40.00 | 13.50 |
| 6.0 mm | 47.10 | 48.00 | 16.20 |
| 8.0 mm | 62.80 | 64.00 | 21.60 |
| 10 mm | 78.50 | 80.00 | 27.00 |
| 12 mm | 94.20 | 96.00 | 32.40 |
| 15 mm | 117.75 | 120.00 | 40.50 |
| 20 mm | 157.00 | 160.00 | 54.00 |
Full-sheet weights — standard UK mild steel sheet sizes
| Thickness | 8×4 (2.5m × 1.25m) | 2m × 1m | 3m × 1.5m |
|---|---|---|---|
| 1.0 mm | 24.5 kg | 15.7 kg | 35.3 kg |
| 2.0 mm | 49.1 kg | 31.4 kg | 70.7 kg |
| 3.0 mm | 73.6 kg | 47.1 kg | 106.0 kg |
| 6.0 mm | 147.2 kg | 94.2 kg | 211.9 kg |
| 10 mm | 245.3 kg | 157.0 kg | 353.3 kg |
Box section, bar & tube — how weight is calculated
Weight per metre = cross-sectional area (m²) × density (kg/m³). The calculator does this for you; the formulas are:
- Flat bar (width w, thickness t): area = w × t
- Round bar (diameter d): area = π/4 × d²
- Square bar (side a): area = a²
- Square box / SHS (side a, wall t): area = a² − (a − 2t)²
- Rectangular box / RHS (a × b, wall t): area = a×b − (a − 2t)(b − 2t)
- Equal angle (leg a, thickness t): area = 2at − t²
- Round tube / CHS (outside dia D, wall t): area = π/4 × (D² − (D − 2t)²)
Common mild steel section weights (kg per metre)
Hollow sections and angles below are the official catalog masses to BS EN 10219 (cold-formed hollow sections) and BS EN 10056 (equal angles) — these account for the corner and root radii of real rolled sections. Flat and round bar are exact (geometry × density). The calculator above gives a theoretical sharp-corner value that will read a little differently on hollow sections and angles; use these figures or the manufacturer's table when exact mass matters.
| Section | Size | kg/m | Basis |
|---|---|---|---|
| Square box (SHS) | 25 × 25 × 2 mm | 1.36 | BS EN 10219 |
| Square box (SHS) | 40 × 40 × 3 mm | 3.30 | BS EN 10219 |
| Square box (SHS) | 50 × 50 × 3 mm | 4.25 | BS EN 10219 |
| Rectangular box (RHS) | 50 × 30 × 3 mm | 3.30 | BS EN 10219 |
| Equal angle | 50 × 50 × 5 mm | 3.77 | BS EN 10056 |
| Equal angle | 25 × 25 × 3 mm | 1.12 | BS EN 10056 |
| Flat bar | 50 × 6 mm | 2.36 | Exact |
| Round bar | 20 mm dia | 2.47 | Exact |
| Round bar | 12 mm dia | 0.89 | Exact |
Why weight matters when you order
Steel is heavy, and weight drives how your order is delivered and offloaded. As a rule of thumb, anything over ~25kg needs two people, and full sheets or long sections need mechanical offloading. Use the figures above to plan site access and lifting before delivery. See our delivery & lead times for how each range is sent.
Order metal cut to size
Browse the ranges these weights apply to: mild steel sheet & plate, box, angle, channel & bar, and RSJ beams & columns. For beam and column section weights specifically, see our steel beam size chart. Everything is available cut to size with free UK mainland delivery on steel.