Electrical Current Calculator

Calculate operating current load in Amps and recommended breaker size

Load Specs

W
System Phase
Power Factor
Adjust Power Factor1

Calculated Line Current

12.50 Amps

Active operating current load.

Recommended Breaker Size

20 Amp

Continuous load breaker sizing (1.25x load factor).

Total Power Input

1,500 Watts

Equivalent to 1.500 kW.

Equivalent Horsepower

2.01 HP

Standard mechanical motor horsepower equivalent.

Current Sizing Rules

Calculations are derived from basic alternating current power formulas:

  • Single Phase Current: Current (I) = Power (P) / (Voltage (V) × PF)
  • Three Phase Current: Current (I) = Power (P) / (1.732 × Voltage (V) × PF)

The 125% Rule: The National Electrical Code (NEC) requires that branch circuit overcurrent protection devices (circuit breakers or fuses) be sized at **125% of continuous loads** plus 100% of non-continuous loads. This prevents nuisance tripping under heating conditions.