Job examples
- Material for a round run10 ft of 12" round, 26 ga.31.42 sq ft of sheet, 28.5 lb.
- Planning a lift20 ft of 24 × 12, 24 ga, plus 15% for seams.159.5 lb, plan the hoist or two guys.
- Kitchen exhaust riser12 ft of 18 × 18 stainless, 22 ga.93.8 lb.
How it's calculated
Sheet area = perimeter × length (round πD, rectangular 2(W+D), oval πb + 2(a−b)). Galvanized uses standard galvanized sheet weight per sq ft by gauge (includes the zinc coating). Mild steel, stainless and aluminum use the nominal gauge thickness × material density. Duct metal only: no reinforcement, hangers, insulation or liner.