What is the minimum electrical service size for my home?
The minimum service size is determined by your calculated demand load. Most modern homes require at least 100-amp service, with 200-amp being common for homes over 2000 sqft or with significant electric appliances. See also our Box Fill Calculator.
How is the general load calculated for living space?
General load is calculated at 3VA per square foot of living space according to NEC 2023. This covers lighting and general receptacles throughout the home.
What are demand factors and why are they applied?
Demand factors account for the fact that not all electrical loads operate simultaneously. The NEC specifies demand factors to prevent oversizing electrical services while maintaining safety.
Do I need to include every appliance in the calculation?
You should include all permanently connected appliances and major loads. Plug-in appliances are typically covered by the general load calculation unless they have significant power requirements.
What if my appliance nameplate rating differs from the default values?
Always use the actual nameplate rating from your appliances for the most accurate calculation. The default values are typical examples but actual ratings can vary significantly.
Can this calculator be used for commercial properties?
This calculator is designed for residential applications only. Commercial load calculations follow different NEC requirements and demand factors.
How often should electrical load calculations be updated?
Recalculate your electrical load whenever you add major appliances, HVAC systems, EV chargers, or make significant home additions that increase the electrical demand. You might also find our Panel Schedule Calculator useful.