Roof Truss Calculator
Truss Dimensions & Count
Calculate truss dimensions and quantity needed
Truss Cost Estimate
Estimate the cost of roof trusses for your project
Formula
Truss Count = (Building Length × 12 / Spacing) + 1 | Rise = Half Span × Pitch/12 | Rake Length = √(Half Span² + Rise²)
Frequently Asked Questions
How many roof trusses do I need?
Divide the building length (in inches) by the truss spacing (16" or 24" OC) and add 1. Example: 40-foot building at 24" OC = (480/24) + 1 = 21 trusses. Add gable end trusses and any hip trusses as needed.
How much do roof trusses cost?
Common trusses: $3-$5 per foot of span ($90-$150 for a 30-ft span). Scissor trusses: $5-$8 per foot. Attic trusses: $7-$10 per foot. Prices vary by region, materials market, and complexity. Delivery and crane setting add $300-$800.
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