🏗️ Roof Truss Calculator (Estimator)
Plan truss counts and approximate member lengths from building size, pitch, spacing, and overhang. Not a structural design tool — always use engineered truss drawings for permits.
Eave-to-eave width (without overhangs).
Length along ridge (used to count trusses).
Enter the rise value in a rise:12 ratio (e.g., 6 = 6:12).
Common spacings: 16, 19.2, 24 in.
Horizontal overhang each side (adds to top chord length).
Results will appear here
📌 Enter building width & length, pitch, spacing, and optional overhangs.
ℹ️ Assumptions & Notes
- Top chord length is calculated along the slope from wall plate to ridge plus the sloped projection of the eave overhang.
- Bottom chord length is approximated as the building width (eave-to-eave without overhang).
- Truss count places interior trusses at uniform spacing along length, plus 2 gable ends if selected.
- Roof area uses the standard pitch multiplier: √(1+(rise/12)²) × plan area.
- This tool is for layout estimating; final truss design must be engineered and meet local code loading.