🔩Metal Roofing Calculator
Count metal roof panels, screws, ridge cap and trim for a gable roof.
Your roof
You'll need about
28 panels
1073 sq ft of roof (two sides) · 859 screws · 40 ft ridge cap · 134 ft trim
sq ft
1073
screws
859
ridge cap ft
40
trim ft
134
🛒 Shopping list
- Metal panels (14 ft)28 panels
- Roofing screws (bag of 250)4 bags
- Ridge cap (10 ft)4 pieces
- Eave & rake trim (10 ft)14 pieces
Order panels long enough to run from eave to ridge in one piece whenever you can — fewer laps, fewer leaks.
How it works
Slope length = (span ÷ 2) × √(1 + (pitch ÷ 12)²). Roof area = 2 × length × slope length. Panels per side = eave length ÷ panel coverage width, times rows needed to reach the ridge. Screws ≈ 0.8 per sq ft. Ridge cap = building length. Trim = both eaves + four rakes.
Worked example
A 40 × 24 ft building at 6/12 pitch: slope 13.42 ft, roof area 1,073 sq ft. With 36 in panels 14 ft long, that's 14 per side = 28 panels, about 859 screws, 40 ft of ridge cap and 134 ft of trim.
Questions people ask
The panel's effective coverage, often 36 in — not its full width.
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Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.