Apr 7, 2026 — Clifton

Wood Truss Sizer

You're picking a truss for a roof span and the span table is a grid of depths, spacings, and load conditions that you always read backwards — you know the span, and you need the minimum depth. This sizer reads it forward: enter your span, spacing, and live load, and it tells you which truss configurations work and draws the profile. Use it in early design to check whether your roof span needs a 2×6 or a 2×10 top chord.

Purpose: reveals the depth penalty of longer spans and tighter spacing — and shows exactly which HVAC ducts fit inside each truss depth.
Load Type
Spacing

Spans are clear, inside to inside, for bottom chord bearing. Deflection limit is L/240 for total load on roofs, L/360 for residential floors, L/480 for commercial floors. #2 Southern Pine, fb = 1550 psi. Roof spans include +15% short-term stress increase.

Next improvement: The likeliest next improvement is adding cost-per-lineal-foot estimates by chord size — so you can see the price jump between a 24" and 28" deep truss at your span.

Future: Rafter Span Table — conventional rafter sizing (not trussed) for different species, grades, and load conditions, from AWC Span Tables for Joists and Rafters.

Future: Steel Joist Selector — open-web steel joist designation, depth, and weight for a given span and load, from SJI Standard Specifications and load tables.