kW to Amps Calculator
Convert kilowatts (kW) to amps instantly. Enter power, voltage, and power factor to calculate current for any electrical system.
Formula & How It Works
Single Phase: Amps = (kW × 1000) / (Volts × PF)
Three Phase: Amps = (kW × 1000) / (√3 × Volts × PF)
Power factor (PF) represents the ratio of real power to apparent power. Resistive loads like heaters have PF = 1.0. Motors typically have PF = 0.8-0.9. The square root of 3 (1.732) appears in three-phase formulas because three-phase power delivers current across three conductors 120° apart.
kW to Amps Conversion Table
Three-phase, 240V, PF = 0.9:
| kW | 120V (1-phase) | 240V (1-phase) | 240V (3-phase) | 480V (3-phase) |
|---|---|---|---|---|
| 1 kW | 9.26 A | 4.63 A | 2.67 A | 1.34 A |
| 2 kW | 18.52 A | 9.26 A | 5.35 A | 2.67 A |
| 5 kW | 46.30 A | 23.15 A | 13.36 A | 6.68 A |
| 10 kW | 92.59 A | 46.30 A | 26.73 A | 13.36 A |
| 15 kW | 138.89 A | 69.44 A | 40.09 A | 20.05 A |
| 25 kW | 231.48 A | 115.74 A | 66.82 A | 33.41 A |
| 50 kW | 462.96 A | 231.48 A | 133.64 A | 66.82 A |
| 100 kW | 925.93 A | 462.96 A | 267.27 A | 133.64 A |
When to Use kW to Amps Conversion
- Sizing circuit breakers and conductors for motor loads
- Selecting generator capacity for known kW loads
- Calculating solar inverter DC input current from kW output
- Determining EV charger circuit requirements
- Sizing transfer switches for standby generators
- Calculating battery bank discharge current for inverters
Frequently Asked Questions
How do I convert kW to amps?
For single phase: Amps = (kW × 1000) / (Volts × Power Factor). For three phase: Amps = (kW × 1000) / (1.732 × Volts × Power Factor). For example, 5 kW at 240V single-phase with PF 0.9 = (5000) / (240 × 0.9) = 23.15 amps.
What is power factor and why does it matter?
Power factor is the ratio of real power (kW) to apparent power (kVA). Resistive loads like heaters and incandescent lights have PF = 1.0. Inductive loads like motors, transformers, and fluorescent lights have PF = 0.7-0.9. Lower power factor means more current is needed for the same real power.
How many amps is 10 kW at 240V?
At 240V single-phase with PF = 0.9: 10,000 / (240 × 0.9) = 46.3 amps. At 240V three-phase: 10,000 / (1.732 × 240 × 0.9) = 26.7 amps. Three-phase systems deliver the same power with less current per conductor.
How many amps is 7.2 kW at 240V?
This is a common EV charger rating. At 240V single-phase with PF = 1.0 (resistive): 7,200 / 240 = 30 amps. This requires a 40-amp breaker and 8 AWG copper wire per NEC guidelines.
Why is three-phase current lower than single-phase?
Three-phase power uses three conductors 120° apart, allowing more efficient power delivery. The square root of 3 (1.732) factor means three-phase delivers the same kW at roughly 58% of the current per phase compared to single-phase. This allows smaller wires and breakers for the same power output.