A 200A residential service at 240V can deliver a maximum demand of 48,000 VA (200A × 240V). In practice, after applying NEC demand factors, a 200A service can typically support a 3,000–4,000 square foot all-electric home with electric heat, or a larger home with gas heating where electric loads are more modest. The NEC optional method typically allows more load than the standard method, which is why most large-home calculations use the optional method. This calculator shows whether your proposed dwelling load fits within a 200A service or whether a 320A or 400A service would be needed.
NEC 220.82 optional method: General load = (3,500 × 3) + 3,000 + 1,500 + 5,000 + 12,000 + 1,200 = 33,200 VA. First 10,000 at 100% + 23,200 at 40% = 19,280 VA. Add AC + EV at 100% = 10,000 + 9,600 = 19,600 VA. Total = 38,880 VA → 162A. Fits within 200A service.
This is a variant of the full Dwelling Load Calculator — which supports both the NEC standard and optional methods with all appliances, HVAC, and EV charger loads.
Try all options in the full Dwelling Load Calculator →