Motor Power & Current Calculator

Calculate motor Full Load Amperes (FLA), inrush starting current, and recommended circuit breaker, overload relay, and copper cable cross-section for 3-phase or 1-phase AC motors.

Induction motors typically 0.80–0.89
IE2/IE3 high-efficiency motors ~85%–94%
Direct-on-Line (DOL) is approx. 5–7x

Results & Sizing

Rated Power (kW)— kW
Full Load Current In— A
Est. DOL Starting Current— A
Rec. Circuit Breaker (Type D)— A
Thermal Relay Setting Range— A
Min Rec. Copper Cable Size— mm²

Formulas

3-Phase: In = P(W) / ( √3 × UL × cosφ × η )

Single Phase: In = P(W) / ( U × cosφ × η )

1 HP ≈ 0.7457 kW