NEC Load Calculation Calculator
Calculate electrical load requirements for residential and commercial buildings based on NEC standards. Determine service size, circuit requirements, and compliance.
Step 1: Building Details
Understanding Load Calculations
NEC load calculations determine the minimum electrical service size required for a building. They account for general lighting, appliances, HVAC, and apply demand factors per NEC Article 220.
Step 2: Load Details
About Demand Factors
Demand factors account for the fact that not all electrical loads operate simultaneously. NEC specifies different demand factors for lighting, appliances, and HVAC systems based on building type and usage.
NEC Load Calculation Results
Required Service Size
Electrical Service Comparison
| Service Size | Max Load (VA) | Typical Use | Wire Size (Cu) | Breaker Type |
|---|
Load Breakdown Analysis
NEC Load Calculation Formula
Demand Load = (Lighting Load + Appliance Load + HVAC Load + Large Appliances) × Demand Factor
Total connected load is calculated first, then demand factors are applied per NEC Article 220. The result determines minimum service size, wire gauge, and circuit protection requirements.
Need Professional Electrical Advice?
Connect with licensed electrical engineers and contractors for NEC compliance verification, load study analysis, and electrical system design for your building project.
Get Professional Electrical Advice