Updated on Oct 12, 2026
Span Check: rafters only. Floor and ceiling joists, headers and beams are withdrawn; the joist data did not pass a check against IRC 2021. Box Fill: isolated grounding conductors count with the others. Standard breaker sizes start at 10 A (A/C keeps 15 A). Saved calculations in both can read differently. Concrete, Footing: Width is entered in feet; the field was labelled inches. NEC 690 Reference: NEC 2023 or 2026, tables replaced by guides.
