Metal Siding Calculator
Calculate total square footage, panel requirements, and estimated costs.
Estimation Summary
How to Estimate Metal Siding for Your Project
Metal siding is a durable, low-maintenance choice for residential, agricultural, and industrial buildings. To accurately estimate the materials needed, you must account for the gross wall area, subtract any openings like windows and doors, and include a waste factor for overlapping and cutting.
The Calculation Process
Our calculator uses the following logic to determine your project needs:
- Gross Surface Area: Calculated by multiplying the total length of your walls by the height.
- Net Surface Area: We subtract the area of openings (windows, doors, garage doors) from the gross area.
- Waste Factor: Metal panels require cutting around gables and openings. A standard 10% waste factor is typical for simple rectangular buildings, while 15-20% may be needed for complex rooflines.
- Linear Foot Conversion: Because metal siding is often sold by the linear foot based on a specific panel width (commonly 36 inches), we convert the square footage to linear footage for easier ordering.
Example Calculation
If you have a wall that is 40 feet long and 10 feet high:
- Gross Area: 40 ft x 10 ft = 400 sq ft.
- Openings: One door (20 sq ft) and two windows (30 sq ft) = 50 sq ft total.
- Net Area: 400 – 50 = 350 sq ft.
- With 10% Waste: 350 x 1.10 = 385 sq ft.
- Linear Feet: If using 3-foot (36″) wide panels, you would need 128.3 linear feet of material.
Expert Tips for Metal Siding Installation
When ordering, always remember to include accessories like J-channels, corner trim, and specialized fasteners with neoprene washers to ensure a watertight seal. Metal siding expands and contracts with temperature changes, so never over-tighten screws; leave a small gap to allow for natural thermal movement.