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Carport Calculator — Layout, Materials & Cost

Plan a freestanding steel carport with an editable post grid, roof, sheets, framing lengths, footings, fasteners and a transparent preliminary material budget.

Carport layout editor

Set the footprint and spacing targets. The plan snaps them into equal bays and builds a preliminary material list.

Start with a common size

Size and roof

Layout targets
Footings and weight
Preliminary frame6 posts · 5 frames

2 equal bays at 10.0 ft · 14.2 ft sheet length · 9.5° pitch

Plan and front elevation

Post and frame positions update with every input.
Steel carport layoutTop plan and front elevation of a steel carport.
PostsFrames / raftersDrawing is schematic, not to scale vertically
Actual post bay10.0 ft
Roof area + 10%343 ft²
Roofing sheets8 × 14.2 ft
Concrete0.82 yd³

Cut and quantity list

Posts6 · 8.0 ft each
Side/eave beams40.0 ft
Rafters5 frame lines · 71.0 ft total
Purlins6 rows per slope · 132.0 ft
Roof sheets8 · 14.2 ft long
Gutter22.0 ft
Estimated frame steel291.0 ft · 965 lb

Planning checks

Actual post spacing10.0 ft ≤ target
Roof pitch2.0:12 · 9.5°
Roof styleMono-pitch · one slope
Diagonal check23.3 ft
Roofing allowance10% included in area
Engineering verificationRequired before construction
Layout quantities are not a structural approval. A qualified designer must select member sections, connections, bracing and footings for local wind, snow, seismic, soil and building-code requirements. Confirm roof pitch and support spacing against the exact roofing manufacturer's tables.

Solved, editable carport projects

Each project restores every layout, weight, roofing, footing and budget assumption. Supplier prices start at zero.

Purchase list and material budget

Turn the calculated frame into an editable early-stage budget. Rates stay visible and can be replaced with supplier quotes; quantities update from the layout above.

New: order estimate
Posts · 48.0 ft$4.50/ft$216.00
Beams, rafters and purlins · 243.0 ft$3.50/ft$850.38
Roofing with 10% waste · 343 ft²$2.75/ft²$944.55
Concrete · 0.82 yd³$170.00/yd³$139.08
160 fasteners · 1 box$32.00/box$32.00
Hardware and deliveryentered$250.00
$2,432.01 subtotal × 1.10 contingency = $2,675.21
This is a purchasing estimate, not a supplier quote or structural design. Member sizes, bracing, connections, fastener pattern, coatings and foundations must be verified for the site and exact products.

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.

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