Steel Carport Calculator — Layout & Materials
Plan a freestanding steel carport with an editable post grid, mono-pitch or gable roof, roofing sheets, framing lengths, footings and an estimated steel weight.
Carport layout editor
Set the footprint and spacing targets. The plan snaps them into equal bays and builds a preliminary material list.
Size and roof
Two 10 ft bays · 12.2 ft roof run · 3.3° pitch
Plan and front elevation
Post and frame positions update with every input.Cut and quantity list
Planning checks
What this carport calculator estimates
The editor turns an overall footprint into equal post bays, frame lines, sloping roof length, roofing sheets, purlins, gutters, concrete footings and an approximate steel weight. It is useful for early budgeting and discussing a project with a fabricator.
How the post layout works
The target spacing is a maximum planning interval: the calculator rounds the number of bays up, then divides the full length evenly. Each side receives one post at every bay line. Changing 20 ft at a 10 ft target therefore creates two bays and six posts.
Roof pitch and sheet count
Pitch is entered as rise per 12 units of horizontal run. Sheet length follows the slope, while sheet count follows carport length divided by the panel's effective cover width. Use effective cover—not the loose sheet width—and verify the profile's minimum pitch.
Material assumptions
Roof area includes 10% ordering allowance. Purlin rows are rounded up along each roof slope. Estimated steel weight uses the editable mass per length for posts and the remaining frame members; brackets, plates, bolts and roofing weight are excluded.
Frequently asked questions
Can I use the calculated spacing to build the carport?
No. It is a clean layout target, not a verified structural span. Wind uplift, snow, member grade, connections, bracing, exposure and soil can all govern the final design.
Why does the calculator change my target spacing?
It creates a whole number of equal bays that do not exceed the target. Equal spacing makes the drawing and material takeoff practical.
Does it work for attached carports?
The quantities can help with an early estimate, but the model assumes two post rows. An attached ledger, its fixings and the existing building require a separate design.
