kVA to Amps Calculator
kVA to amps for single-phase and three-phase circuits. No power factor needed.
The formulas
1-phase: A = 1000 × kVA / V
3-phase: A = 1000 × kVA / (√3 × V)
A 50 kVA three-phase transformer at 400 V supplies up to 72 A per line; the same rating single-phase at 230 V would be 217 A, which is why anything sizeable runs on three phases.
Why kVA and not kW
Transformers and generators are limited by the current their windings can carry, regardless of how much of that current does useful work. So their nameplates are in kVA (volts times amps) and the conversion to amps needs no power factor at all. To get real kilowatts out of a kVA rating, multiply by the load's power factor: a 50 kVA set feeding motors at PF 0.8 delivers 40 kW.