Calculator InputLive calculation
kW to Amps 3 Phase Calculator
Pre-configured for three-phase AC circuits. Adjust values below.
Conversion Result
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Enter values to calculate
Formula Used
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Watts
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Milliamps
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Horsepower
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BTU/hr
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How kW to Amps 3 Phase Works
1
Enter the power in kilowatts (kW)
Use the total three-phase power rating from the motor nameplate or load schedule.
2
Enter the line-to-line voltage (V)
Three-phase voltage is measured between any two line conductors. Common values are 208V, 380V, 400V, 415V, and 480V.
3
Enter the power factor (PF)
Three-phase motors typically operate at PF 0.80 to 0.90. Use PF 0.85 as a standard default for mixed industrial loads.
4
Read the line current in amps
The result is the per-phase line current. All three phases carry equal current in a balanced load.
kW to Amps 3 Phase Formula
Three-Phase ACI = (kW × 1000) ÷ (√3 × V × PF)
Standard formula. √3 ≈ 1.732 accounts for the phase geometry.
Per-Phase PowerI = (kW × 1000) ÷ (3 × Vph × PF)
Alternative using phase voltage (Vph = VLL ÷ √3).
ReversekW = (√3 × V × I × PF) ÷ 1000
Convert three-phase amps back to kilowatts.
The three-phase kW to amps formula is I = (kW × 1000) ÷ (√3 × V × PF), where √3 equals approximately 1.732.
For example, a 10 kW three-phase load at 415V with PF 0.85 draws: I = (10 × 1000) ÷ (1.732 × 415 × 0.85) = 16.37 amps per phase.
Three-phase power distributes load across 3 conductors, which reduces the current per conductor compared to single-phase at the same power level. Industrial motors, HVAC chillers, and commercial kitchen equipment typically use three-phase power.
Frequently Asked Questions
The √3 factor (1.732) arises because three-phase voltages are offset by 120 degrees. The geometric relationship between line-to-line and phase voltages introduces this constant.
Use the line-to-line voltage, not the phase voltage. Common values: 208V (US commercial), 380V (Europe), 400V (IEC standard), 415V (UK/Australia), 480V (US industrial).
15 kW at 415V three-phase with PF 0.85 equals 24.55 amps per phase.
Yes. Three-phase delivers the same power with less total conductor current, smaller wire gauges, and smaller circuit breakers. It also produces smoother torque in motors.
Induction motors at full load typically have PF 0.80 to 0.90. At partial load, the PF drops. Synchronous motors can operate at PF 1.0 or even leading PF.