Demand Load Calculator
Calculate residential service demand load per NEC Article 220: general lighting, appliances, HVAC, and service size.
Inputs
sq ft
NEC Table 220.12: 3 VA/ft² for dwellings; demand factors per NEC Table 220.42
circuits
NEC 210.11(C)(1): minimum 2 kitchen small appliance circuits × 1,500 VA = 3,000 VA
circuits
VA
VA
VA
NEC 220.51: electric heating at 65% demand; NEC 220.60: count only larger of AC vs. heat
VA
Results
Calculated Demand Load
24,785 VA
Minimum Service Size
125 A
General Lighting Load6,600 VA
Small Appliance + Laundry4,500 VA
Total Connected Load32,300 VA
How to Use This Calculator
- Enter the Floor Area in m² — NEC Article 220 assigns 33 VA/m² for general lighting in dwellings.
- Enter the number of Kitchen Small Appliance Circuits (NEC minimum is 2) and Laundry Circuits (minimum 1).
- Enter the total Fixed Appliance Loads in VA — sum nameplate VA for range, dryer, dishwasher, and water heater.
- Enter the Air Conditioning Load and Electric Heating Load in VA — NEC uses the larger of the two with a 65% demand factor on heating.
- Enter the EV Charger Load in VA if applicable (e.g., Level 2 at 240V × 30A = 7,200 VA) — counted at 100% demand.
- Read the Calculated Demand Load in VA and the Minimum Service Size in amperes to select the correct service entrance equipment.
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