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MetalCalc cost methodology

MetalCalc provides an early project-planning range. It is not a contractor quote, appraisal, bid, engineering opinion or promise of market price. The calculator uses a shared set of Low, Typical and High unit-rate assumptions, then applies those assumptions to the project information selected by the user.

What the three ranges mean

Low, Typical and High are independent scenarios. Each scenario uses the matching price tier for the building package, concrete, erection, optional systems and fixed allowances. A planning contingency of 5%, 10% and 15% is added respectively. The range is deliberately broad because supplier scope and local conditions differ.

Geometry and structural package

Floor area equals width multiplied by length. Roof and wall areas use a conceptual symmetrical 4:12 roof. Structure rates are multiplied by continuous size and eave-height factors. Interpolation prevents a slightly larger building from producing a lower structural total at a pricing boundary.

Frame and scope treatment

Tubular installed-shell research commonly packages erection with the building price, so MetalCalc does not add a second erection charge. Red iron projects show the kit and erection separately. When a user selects Not Sure, the calculator presents two complete alternatives instead of mixing the low price from one structural system with the high price from another.

Foundation planning

A slab is not treated as a complete structural foundation. Four-inch and six-inch selections include the slab, a conceptual perimeter-based structural-footing allowance and foundation engineering. Heavy Duty includes a heavier slab and footing allowance. None of these calculations determine footing dimensions, reinforcement, piers, grade beams, anchors or soil suitability.

Location and optional systems

The state selection maps to a broad labor region. That multiplier applies only to itemized red-iron erection and site preparation. Concrete, materials, freight and optional systems use broad national planning ranges. Electrical combines a service allowance with an area allowance. HVAC uses conditioned area and, for Commercial HVAC, a separate equipment addition.

Supported range and exclusions

The numeric model supports 600–10,000 square feet, 8–24 foot eave height and the contiguous United States. Alaska, Hawaii, larger industrial work and custom aircraft-hangar doors require project-specific pricing. Sales tax, land, financing, demolition, utility extensions, interior finishes, fire sprinklers and unusual remediation are excluded.

Data maintenance

Public supplier prices, government schedules and industry cost guides inform the planning ranges. Each amount is normalized by scope before use. Pricing version 2026-08-01-planning.2 was reviewed on 2026-08-01. MetalCalc reviews assumptions periodically; a newer version can change results without changing the underlying formula.