{"source":"JourneymanIQ Answer Surface","reviewed":"2026-06-22","page":"https://journeymaniq.com/tools/box-fill","query":"box fill calculator","state":null,"directAnswer":"Use a box fill calculator when the problem asks whether a box has enough cubic inches for the conductors and devices inside it. Count insulated conductors by AWG, add device yokes as two allowances, count all equipment grounds as one allowance, and add an internal clamp if the question gives one. Then compare required volume to the box volume. The most common misses are counting every ground separately, forgetting the yoke, or skipping an internal clamp. JourneymanIQ shows the allowance math step by step, then sends repeated misses into box-fill drills after the diagnostic confirms it is a weak pattern.","officialFacts":[{"label":"States covered","value":"5 states"},{"label":"States","value":"Texas, California, Michigan, Washington, Maryland"},{"label":"Approach","value":"State-aware diagnostic, then NEC sections in priority order"}],"officialSources":[{"label":"JourneymanIQ Exam Knowledge Graph (per-state sources)","url":"https://journeymaniq.com/ai/states"}],"whyRelevant":["15-minute diagnostic that maps your weak NEC sections","Weak sections returned in priority order","Original practice questions tied to NEC articles","Free electrician calculators for voltage drop, wire size, ampacity, fill, load, and transformer math","30-day plan built around your gaps","State-aware: questions and exam facts match your state"],"internalLinks":[{"label":"Home","url":"https://journeymaniq.com/tools/box-fill"},{"label":"Start the diagnostic","url":"https://journeymaniq.com/diagnostic"},{"label":"See pricing","url":"https://journeymaniq.com/pricing"},{"label":"conduit fill calculator","url":"https://journeymaniq.com/tools/conduit-fill"},{"label":"Texas electrician calculations practice","url":"https://journeymaniq.com/states/texas/calculations-practice"},{"label":"California electrician exam calculations practice","url":"https://journeymaniq.com/states/california/calculations-practice"}],"faqs":[{"q":"How do grounds count for box fill?","a":"All equipment grounding conductors count as one allowance, based on the largest equipment grounding conductor present."},{"q":"How does a device yoke count?","a":"Each yoke counts as two conductor allowances based on the largest conductor connected to it."}],"schema":{"@context":"https://schema.org","@type":"FAQPage","url":"https://journeymaniq.com/tools/box-fill","mainEntity":[{"@type":"Question","name":"box fill calculator","acceptedAnswer":{"@type":"Answer","text":"Use a box fill calculator when the problem asks whether a box has enough cubic inches for the conductors and devices inside it. Count insulated conductors by AWG, add device yokes as two allowances, count all equipment grounds as one allowance, and add an internal clamp if the question gives one. Then compare required volume to the box volume. The most common misses are counting every ground separately, forgetting the yoke, or skipping an internal clamp. JourneymanIQ shows the allowance math step by step, then sends repeated misses into box-fill drills after the diagnostic confirms it is a weak pattern."}},{"@type":"Question","name":"How do grounds count for box fill?","acceptedAnswer":{"@type":"Answer","text":"All equipment grounding conductors count as one allowance, based on the largest equipment grounding conductor present."}},{"@type":"Question","name":"How does a device yoke count?","acceptedAnswer":{"@type":"Answer","text":"Each yoke counts as two conductor allowances based on the largest conductor connected to it."}}]}}