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kW to Amps Calculator

Kilowatts to amps at any voltage, for DC, single-phase and three-phase circuits.

kW
A
V
230 V in Europe, 120/240 V in North America, 400 V three-phase.
1 for heaters and resistive loads, 0.8 to 0.9 for motors.

The formulas

DC: A = 1000 × kW / V
1-phase: A = 1000 × kW / (V × PF)
3-phase: A = 1000 × kW / (√3 × V × PF)

5 kW at 230 V single-phase with PF 1 draws 21.7 A. The same 5 kW as a motor load (PF 0.85) draws 25.6 A, and on a 400 V three-phase feed only 8.5 A per line.

Why power factor matters

Kilowatts measure real power, the part that does work. Motors, transformers and old-style fluorescent ballasts also draw reactive current that does no work but still heats the wiring, so the amps are higher than kW alone suggests. Cable sizing and breaker choice must use the real current, which is why every AC formula here divides by the power factor. Three-phase uses line-to-line voltage (400 V in Europe, 480 V in US industry) and splits the load across three conductors.