Metal Roofing Calculator
Work out how many metal panels, screws and trim your roof needs.
What you'll need to order
- metal roofing panels
- ridge cap
- eave and rake trim
- closure strips
- roofing screws
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
panels = eave length × 12 ÷ panel coverage width
Use the coverage width, not the overall panel width — a panel sold as 39 inches wide typically covers only 36 inches once lapped. Getting this wrong leaves you a panel short on every roof.
Worked example
With eave length 40 ft, slope length (eave to ridge) 16 ft, panel coverage width 36 in, this calculator returns 13.33 .
Frequently asked questions
How many metal roofing panels do I need?
Divide the eave length in inches by the panel coverage width. A 40 ft eave with 36 inch coverage panels needs 14 panels per slope, rounding up.
What length should I order metal panels?
Most suppliers cut to order, so specify the exact slope length plus 2 to 3 inches of eave overhang. A single full-length panel per slope avoids horizontal laps, which are the most common leak point.
How many screws does metal roofing need?
Roughly 80 per square for exposed-fastener panels — about 1 screw per square foot including laps and trim. Standing seam uses hidden clips instead and the count differs entirely.
What is the minimum pitch for metal roofing?
Exposed-fastener corrugated panels need 3/12 or steeper. Standing seam with sealed seams can go down to 1/4 in 12 on some systems. Below the manufacturer minimum, the warranty is void.