This tool calculates the total electrical load for residential and commercial buildings. It applies demand factor and diversity factor to determine the actual load, and recommends circuit breaker size and cable size. Essential for electrical design and safety compliance.
📐 Load Calculation Formulas
Total Connected Load: Σ (Qty × Wattage) Demand Load: Connected Load × Demand Factor Diversity Load: Demand Load × Diversity Factor Current (A): I = (Load × 1000) / V Breaker Size: I × 1.25 (125% rule)
Where: Qty = Number of appliances Wattage = Power per unit Demand Factor = % of load actually used Diversity Factor = % simultaneous use V = System Voltage (V)
📊 Typical Demand Factors
Building Type
Demand Factor
Diversity Factor
Residential (Small)
70-80%
85-95%
Residential (Large)
60-70%
80-90%
Commercial Office
65-75%
80-85%
Retail Store
70-80%
75-85%
Industrial
75-85%
70-80%
📌 Circuit Breaker Sizing
Continuous Load: Breaker ≥ 125% of continuous load