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Joist count calculator
Floor or ceiling joist count at standard 12″ / 16″ / 19.2″ / 24″ on-center spacing for a given span, plus blocking + rim-joist count.
Joist + framing count
23 regular joists @ 16″ OC
+ 2 rim joists at the ends. Plus 44 blocking pieces across 2 blocking row(s) (1 row per 8 ft of span). Total sticks: 25 + blocking.
Standard formula: count = floor(perpendicular ÷ spacing) + 1. Blocking row count per IRC R502.7 / IBC 2308: rule-of-thumb 1 row per 8 feet of span. Verify the actual blocking spec with the EOR or local AHJ.
Built by Forward
Forward runs joist count, beam deflection, rebar LF, concrete yards, NEC + IBC + IMC calcs over text.