Metal Siding Calculator

Metal siding is usually steel or aluminum, and the two behave differently. Steel is stronger and resists dents, but a deep scratch that exposes bare metal can rust if the coating isn’t touched up. Aluminum won’t rust, but it dents more easily and is often used where a lighter panel matters. Steel is commonly sold by gauge, where a lower number means thicker metal, so compare gauges rather than brands when you’re pricing. See metal siding cost for typical price ranges.

Many metal panels are formed to length rather than sold in fixed sizes, and vertical panels often run the full height of the wall. If that’s your product, count panels by width instead of area: divide the wall’s width by the panel’s coverage width, round up, and add extra panels for the triangular gable sections. The area-based estimate above is a good cross-check, but the width count is what the supplier will actually cut and ship. The gables, garages and sheds guide shows how to measure the gable sections.

Long, flat metal panels can show “oil canning”, a slight visible waviness. Ribbed or striated profiles hide it better than smooth flat panels. Metal also expands and contracts with temperature, so follow the manufacturer’s fastener spacing rather than driving every fastener tight.