Electrical Load Calculators

Calculate residential and commercial electrical loads using NEC Article 220 standard method demand factors. Size your service entrance and overcurrent protection devices accurately.

NEC Article 220 Standard Method 3 Calculators

Residential (Dwelling Unit) Load Calculator

NEC 220.40–220.60

Standard method load calculation for a single dwelling unit. Calculates total demand load and recommended service size per NEC Article 220.

Appliances
HVAC (larger of AC or Heat used per NEC 220.60)

Commercial Load Calculator

NEC 220.12, 220.42–220.56

Calculate commercial building electrical service load using NEC Article 220 standard method with demand factors for lighting, receptacles, motors, and kitchen equipment.

Breaker / OCPD Sizing Calculator

NEC 240.4, 240.6

Determine the correct standard overcurrent protection device (OCPD) size for a given load. Accounts for continuous load multiplier and standard breaker sizes per NEC 240.6(A).