2×12 SPF Floor Joist Span (16" O.C., 40 PSF)
Largest commonly available SPF joist size. Provides good spans for residential construction while maintaining cost-effectiveness in northern lumber markets.
Results
Maximum Span18'-8"
Maximum Span224inches
Species & GradeSpruce-Pine-Fir #2
Load ConditionLive Load: 40 psf, Dead Load: 10 psf
Deflection LimitLive Load: L/360, Total Load: L/240
Code ReferenceIRC Table R502.3.1
Need to adjust these values? Use the full calculator:
Open Full CalculatorRelated Calculations
2×8 Douglas Fir Floor Joists at 16" O.C.
Calculate maximum span for 2×8 Douglas Fir #2 floor joists spaced 16 inches on center with 40 psf live load.
2×10 Douglas Fir Floor Joists at 16" O.C.
Determine maximum span for 2×10 Douglas Fir #2 floor joists at 16 inches on center.
2×12 Douglas Fir Floor Joists at 16" O.C.
Maximum span calculation for 2×12 Douglas Fir #2 floor joists at 16" O.C. for large open spaces.
2×10 Douglas Fir Floor Joists at 12" O.C.
Span tables for 2×10 Douglas Fir #2 joists at tighter 12 inch on center spacing.
2×10 Douglas Fir Floor Joists at 24" O.C.
Calculate span for economical 2×10 Douglas Fir #2 joists at 24 inch spacing.
2×8 Douglas Fir Floor Joists at 12" O.C.
Maximum span for 2×8 Douglas Fir #2 joists with tight 12 inch spacing.