Formula
Because of its corrugations, a trapezoidal panel contains more steel than the area it covers. Its weight is therefore calculated from the developed width, not the effective width as with flat sheet.
Trapezoidal sheet weight per metre (kg/m) = Thickness (mm) × Developed width (m) × 7.85
Weight per m² of covered area (kg/m²) = Weight per metre ÷ Effective width (m)
The zinc coating adds the value of its class (e.g. 0.275 kg/m² for Z275). Actual weight may deviate 1–3% from the calculated value due to thickness tolerance, coating and paint.
What are developed width and effective width?
A trapezoidal panel is made by roll-forming flat sheet. The width of that flat sheet is the developed width. The corrugations shorten this width, and panels are laid with side overlaps; the width one panel covers after overlap is the effective width. The effective width is always smaller than the developed width.
Trapezoidal sheet weight by thickness
Example geometry: developed width 1250 mm, effective width 1000 mm, Z275 coating. Because the effective width is 1 m, the weight per metre equals the weight per m² of covered area in this example. If your profile differs, use the calculator above.
| Thickness | kg/m and kg/m² | 3 m panel (kg) |
|---|---|---|
| 0.40 mm | 4.27 | 12.81 |
| 0.50 mm | 5.25 | 15.75 |
| 0.60 mm | 6.23 | 18.69 |
| 0.70 mm | 7.21 | 21.64 |
| 0.80 mm | 8.19 | 24.58 |
For flat sheet weight and coil length: Steel Sheet Weight Calculator