Metal Roof Calculator (Tin & Steel)

Divide the roof area by the area one panel covers — the panel’s exposed coverage width times its length — then add waste. Exposed-fastener panels cover about 36 in (3 ft) wide; a 12 ft panel then covers about 36 sq ft. A 1,300 sq ft roof needs about 36 panels, so order around 40 with 10% waste. The calculator works the pitch into the roof area and does the panel count for you.

The coverage (net) width is less than the panel’s overall width, because panels overlap. Exposed-fastener corrugated and ribbed panels (R-panel/PBR) cover about 36 in; 5V-crimp about 24 in; standing seam typically 16 in (12–19 in depending on the profile). Panels are cut to your slope length. Use the coverage width, not the overall width, or you’ll come up short.

Installed, exposed-fastener steel runs roughly $4–$8 per square foot ($400–$800 per square); standing seam is more, about $10–$16 per square foot. Materials alone are a fraction of that — corrugated steel around $1–$3 per sq ft, standing seam $4–$8. Enter your price per square (100 sq ft) and an optional labor rate for a material-plus-labor estimate.

Exposed-fastener panels (corrugated, R-panel) screw through the face — cheaper, faster, and fine for most roofs, but the exposed screws and their gaskets are the wear point over decades. Standing seam hides the fasteners under interlocking seams — pricier, but longer-lived and cleaner-looking. Pick the type in the calculator; it changes the coverage width and the fastener count.

For exposed-fastener panels, budget about 80 screws per square (100 sq ft) — roughly one every 12–18 in along the purlins plus the panel laps. A 1,300 sq ft roof is around 1,050 screws before waste. Standing seam uses far fewer visible fasteners because concealed clips hold the panels; the calculator adjusts the count for the type you pick.

No — the panel count is the same for a given profile and coverage width, whatever the metal. What changes is the price and the longevity: “tin roof” today usually means galvanized or Galvalume steel, aluminum resists coastal corrosion, and both come in the same corrugated and standing-seam profiles. Size the panels here, then price them for your chosen metal.