ELECTRICAL LOAD CALCULATOR
Calculate electrical load requirements and recommended panel size per NEC standards
STEP 1: GENERAL LIGHTING & RECEPTACLE LOAD
DWELLING INFORMATION
REQUIRED CIRCUITS
LIGHTING LOAD CALCULATION (NEC 220.12)
General Lighting (2000 sq ft × 3 VA/sq ft):6,000 VA
Small Appliance Circuits (2 × 1,500 VA):3,000 VA
Laundry Circuit (1 × 1,500 VA):1,500 VA
Total Before Demand Factor:10500 VA
After Demand Factor (NEC 220.42):5616 VA
Lighting Load:23.4 Amps @ 240V
STEP 2: FIXED APPLIANCE LOADS
CURRENT APPLIANCES
Electric Range/Oven
Electric Water Heater
APPLIANCE LOAD CALCULATION
Electric Range/Oven:50 A
Electric Water Heater:25 A
Total Appliance Load:75 Amps @ 240V
STEP 3: HEATING & COOLING LOADS
HVAC EQUIPMENT
Note: Only the larger of heating or cooling load is used in calculation (non-coincident loads per NEC 220.60)
HVAC LOAD CALCULATION
Heating Load:12000 W (50 A @ 240V)
Cooling Load:8000 W (33 A @ 240V)
HVAC Load (larger of two):50 Amps @ 240V
STEP 4: SERVICE SIZE CALCULATION & RESULTS
CALCULATION OPTIONS
SERVICE LOAD CALCULATION SUMMARY
Lighting & Receptacle Load:23.4 A
Fixed Appliance Load:75 A
HVAC Load:50 A
Total Connected Load:148.4 A
Total Load w/ Safety Factor (25%):185.5 A
400A
Recommended Panel
60 circuit slots
46.4%
Panel Utilization
214.5A spare capacity
MATERIAL ESTIMATE
Electrical Panel (400A):1 UNIT
Main Breaker (400A):1 UNIT
Circuit Breakers (Assorted):60 SLOTS
NEC CODE COMPLIANCE & TIPS
80% RULE (NEC 220.83)
Service conductors and panels should not exceed 80% of their rated capacity for continuous loads to ensure safe operation.
DEMAND FACTORS (NEC 220.42)
Lighting loads over 3,000 VA apply a 35% demand factor, recognizing that not all loads operate simultaneously.
PROFESSIONAL CONSULTATION
Always consult a licensed electrician for final calculations and installations. Local codes may have additional requirements.
NAMEPLATE RATINGS
Use actual nameplate ratings for appliances when available. Estimates provided are typical values and may vary.
400A PANEL46%
60 CIRCUIT SLOTS
214.5A spare capacity