Deck Joist Span & Cantilever Solver

Lumber Species Spruce-Pine-Fir (SPF) Douglas Fir-Larch Southern Yellow Pine

Joist Dimension 2×6 2×8 2×10 2×12

On-Center Spacing 12″ O.C. (Diagonal Decking) 16″ O.C. (Standard) 24″ O.C.

Maximum Allowable Joist Span

Measured from ledger board to centerline of supporting beam.

Maximum Overhang Cantilever (L/4 Rule)

Per IRC R507.6, cantilevers cannot exceed 1/4 of the backspan.