By occupancy · Article 220 · NEC 2023
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Worked example — for a 5,000 ft² office with forty receptacles, 208 V three-phase, continuous lighting, the engine returns:
81 A calculated — 90 A service · 29,075 VA
How it works. A commercial calculation starts from the lighting load per square foot for the occupancy type, applies the continuous-load factor where it belongs, then adds receptacle, kitchen, show-window and track lighting loads under their own demand rules. Occupancy is the first input because it sets the lighting number everything else builds on.
What this covers: Lighting, receptacles, kitchen equipment, show windows, track lighting and your entered loads. Does NOT include motor loads (use Motor Feeder) or sign circuits (600.5) — add those as other loads.
Educational reference, not code. Based on NEC (NFPA 70) 2023 (220 Pt III · 220.42(A)). Your state or local AHJ may enforce a different edition or amend it — theirs is the one that counts. No NEC text is reproduced here.