Box Fill Pro - Electrician

Box Fill Pro calculates electrical box fill per NEC 2023 Article 314.16 — the code section that determines how many wires, devices, and fittings can legally fit in a junction or device box. Works offline. No subscription. One-time purchase. WHAT IT CALCULATES - Line-voltage conductors by AWG gauge (14, 12, 10, 8, 6) - Equipment grounding conductors (all EGCs combined = one allowance, per 314.16(B)(5)) - Internal cable clamps (all clamps = one allowance, per 314.16(B)(2)) - Luminaire studs and hickeys - Strap-mounted devices (switches, receptacles) VERDICTS BACKED BY CODE Compares your fill total against NEC Table 314.16(A) box capacities. Get an instant PASS or FAIL — and a suggested upgrade if you're overfilled. BUILT FOR THE FIELD No ads. No cloud. No account required. Designed for electricians who need the answer in seconds, not after a signup flow. PART OF THE FIELDMETRIC SUITE Also available: Conduit Fill Pro (NEC conduit fill calculations).