The NEC standard method for dwelling loads (NEC 220.40 through 220.55 in NEC 2023; Article 120 in NEC 2026) calculates demand load by applying specific demand factors to each load category: general lighting at 3 VA per square foot with tiered demand factors from Table 220.42, small appliance and laundry circuits at 1,500 VA each before demand factors, and specific appliances at 100% for the first few and 75% for remaining units. The standard method produces a more conservative result than the optional method for smaller homes and is required by some AHJs for permit submittals. It is also the required method for determining neutral conductor sizing.
NEC 220.40 standard method: Lighting = 1,800 × 3 = 5,400 VA + 3,000 VA SAB + 1,500 VA laundry = 9,900 VA. Demand factor per Table 220.42: first 3,000 VA at 100% = 3,000; next 6,900 VA at 35% = 2,415 VA. Dryer = 5,000 VA. Range per Table 220.55 = 8,000 VA. AC = 6,000 VA. Total demand ≈ 24,415 VA → 24,415/240 ≈ 102A. Use 125A 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 →