Roof Truss Calculator
Estimate top chord length and ridge height for a standard roof truss from span and pitch.
Estimate only — not a substitute for a licensed tradesperson, a certified engineer, or sign-off from your local building surveyor. Verify against current standards and site conditions before ordering materials or starting work.
Result
- Half span + overhang
- 4,450mm
- Top chord length
- 4,816.65mm
- Ridge height above wall plate
- 1,843.25mm
Indicative geometry only. Truss design, member sizing, and bracing must be certified by a registered truss designer/engineer before manufacture.
What this is based on
Governed by AS 1684 and the truss fabricator's engineered design. This calculator estimates geometry only. Never substitute it for the fabricator's layout and tie-down design.
We cite the clause and link to the publisher so you can read the source yourself. We do not reproduce the text or tables of the NCC or of any Australian Standard.