Electrical Load Calculator
Calculate total electrical load and required service panel size for residential and commercial buildings
About this calculator
The Electrical Load Calculator helps determine the total electrical demand for residential and commercial buildings by analyzing all connected appliances, lighting, and equipment. This essential tool calculates the required service panel size and amperage capacity needed to safely power your building. Proper load calculations ensure electrical safety, code compliance, and prevent overloading circuits, making it invaluable for electricians, contractors, and property owners planning electrical installations or upgrades.
How to use
Enter details for all electrical devices, appliances, and systems in your building, including their power ratings in watts or amps. The calculator will sum the total electrical load and recommend the appropriate service panel size. Review the results to ensure your electrical system can handle the calculated demand safely.
Frequently asked questions
What size service panel do I need for my home?
Most modern homes require 200-amp service panels, but smaller homes may use 100-amp panels while larger homes need 400-amp service.
How do I calculate electrical load for appliances?
Add up the wattage or amperage ratings of all appliances, lighting, and electrical systems that could operate simultaneously in your building.
What's the difference between connected load and demand load?
Connected load is the total of all electrical devices, while demand load accounts for the fact that not everything operates simultaneously.