Deck Joist Size for a 12-Foot Span
Reverse lookup: every Table 2 combination whose allowable clear span is at least 12'-0". We filter published cells only—no averaging between spacings.
Combinations that meet ≥ 12'-0"
Comparison uses feet-and-inches strings converted to inches (e.g. 11'-10" = 142″). A cell qualifies when that value is ≥ 144″.
How to read this list
If your clear span (ledger face to beam face) is about 12 feet, pick any row whose table span is at least that long, then confirm species, grade, and spacing match what you will buy. Prefer a little margin—Table 2 already embeds L/360 under 40/10 psf wet service.
Example checks from the same JSON: Southern Pine 2x8 @ 16″ = 11'-10" (meets 10′ and 12′? 11'-10" ≥ 10′ yes, ≥ 12′ no). Southern Pine 2x10 @ 16″ = 14'-0" (meets 14′ exactly). DF-L 2x10 @ 12″ = 15'-8". Redwood-group 2x12 @ 16″ = 15'-1". Use the calculator to pull one cell fast.
Related targets: 10-foot span, 12-foot span, 14-foot span. Spacing primers: 12″, 16″, 24″.
FAQ
Why isn’t there a “9'-6" custom” row?
Because Table 2 does not publish that cell. We never interpolate between 12″ and 16″ columns.
Does meeting span auto-approve overhang?
No—apply LO and L/4 separately on joist overhang.