calcs.homes
calcs.homes
Enter the building length and your on-center spacing and this roof truss calculator returns how many trusses you need — including both gable ends — with an estimated cost.
Estimate only — a truss layout from the manufacturer governs; girder and hip trusses cost more.
We divide the building length by the on-center spacing to get the number of bays, round up, and add one — a run of N bays needs N+1 trusses, the same way a fence with N sections needs N+1 posts. That total already includes a truss at each gable end.
Standard spacing is 24 inches on center for residential roofs, which suits most sheathing and shingle loads. Heavy tile or snow loads, or a roof that also carries a ceiling, sometimes drop to 16 inches on center, which raises the truss count by roughly half.
24 inches on center is standard for residential roofs. 16 inches on center is used for heavy roof loads such as concrete tile, or where the bottom chord carries a finished ceiling with storage above.
Yes. The gable-end trusses are included in the count here. Note that gable-end trusses are often a different (vertical-web) design and are priced separately by the manufacturer.
No — this is a straight common-truss count. Hip sets, girder trusses, and step-downs are engineered for your specific roof and cost significantly more per piece.