Calculator
Three-Phase Motor Current Calculator
Change the inputs to match your equipment. Results update automatically.
Formula
I = (kW x 1000) / (sqrt(3) x V x cos phi x efficiency) Worked example
15 kW shaft output, 400 V, efficiency 0.90 and power factor 0.85 give I = 15000/(√3 × 400 × 0.85 × 0.90) = 28.30 A.
Scope and interpretation
Motor nameplate kW normally describes mechanical shaft output. Starting current and partial-load performance must be checked separately.