Deck Joist Span Calculator by Spacing and Species
Deck joist span changes with on-center spacing because spacing sets tributary load. Species and grade enter through adjusted E, Fb and Fv design values.
deck joist span calculator by spacing and species deck joist span calculator by spacing 2x10 deck joist span
Tributary line load
w = area_load * joist_spacing
Deflection check
delta = 5 * w * L^4 / (384 * E * I)
Permit boundary
This is a transparent engineering screen, not a prescriptive deck span table. Final deck framing still needs adopted code tables or engineered design.
Related pages
- Deck joist span calculator - live span screen for entered spacing and design values.
- Deck beam span calculator - beam span after joist spacing and load are known.
- Deck ledger fastener spacing - ledger fastener spacing from loads and allowable load.
- Deck footing size calculator - post load and footing bearing area.