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Steel Roof Truss Calculator

Steel roof trusses are common in metal buildings, commercial structures, and wide-span agricultural buildings where wood chords would need to be impractically large. This steel roof truss calculator sizes your truss by span and pitch and prices it using steel material rates.

Calculator

Size Your Steel Roof Truss

Enter your building specifications below. Results and the roof diagram update live as you type.

Try an example:
Total width of the building
Length along the ridge
Rise per 12" of run, or switch to an exact angle
Eave overhang beyond wall

Live Roof Diagram

Results

Roof Height
Rafter Length
Roof Angle
Rise
Run
Roof Area
Estimated Lumber
Material Cost
Dead Load
Live Load
Total Weight
Truss Count
Cost Estimator

Estimate Your Project Budget

Automatically calculated from your inputs above in the calculator.

Material$0
Labor$0
Installation$0
Total Estimate $0

Estimates only. Actual costs vary by region, supplier, and site conditions.

Steel Roof Truss Design Basics

Steel trusses use cold-formed or hot-rolled steel members instead of wood, connected with bolted or welded gusset plates rather than the MiTek-style punched connector plates used on wood trusses. This lets steel trusses span much further per truss line with a lower dead weight-to-strength ratio.

Because steel members carry load differently than wood, force analysis (axial tension and compression in each member) is standard practice for steel truss design — this calculator gives a preliminary board-footage-equivalent and cost estimate, not a full force analysis.

Steel roof truss weight and pricing vary significantly by section size and steel grade; use the material cost shown here as a rough planning number and get a quote from a steel building manufacturer for final pricing.

Frequently Asked Questions

Steel roof truss calculator

The Steel truss calculator covers metal members, weight and force analysis.

Steel roof truss design calculator excel

This web calculator covers the same span, pitch, and cost inputs as a typical spreadsheet workflow — no download or Excel required.

See all FAQs