Easily convert Amps to Kilowatts (kW) with our free online calculator. Supports DC, Single-Phase AC, and Three-Phase AC systems. Includes kW formulas and a reference table.
How to Convert Amps to Kilowatts (kW)
To convert Amps (Electrical Current) to Kilowatts (kW), you need to know the voltage of the system and, for AC systems, the power factor. Kilowatts represent the “real power” being consumed by an electrical load, whereas Amps measure the flow of the current.
The Formula
For DC Systems:
kW = (Amps × Volts) ÷ 1,000
For AC Single-Phase Systems:
kW = (Amps × Volts × Power Factor) ÷ 1,000
For AC Three-Phase Systems:
kW = (√3 × Amps × Volts × Power Factor) ÷ 1,000
*√3 is approximately 1.732. Power Factor (PF) usually ranges from 0.1 to 1.0 (standard is often 0.8).
Amps to kW Reference Table
Estimated kW values for common amperage at standard voltages (Single-Phase AC, 0.8 PF):
| Current (Amps) | 120V (1φ) | 240V (1φ) | 480V (3φ) |
|---|---|---|---|
| 10 A | 0.96 kW | 1.92 kW | 6.65 kW |
| 20 A | 1.92 kW | 3.84 kW | 13.30 kW |
| 30 A | 2.88 kW | 5.76 kW | 19.95 kW |
| 50 A | 4.80 kW | 9.60 kW | 33.25 kW |
Key Concepts
Power Factor (PF): In AC circuits, the power factor is the ratio of real power (kW) to apparent power (kVA). It accounts for the inefficiency caused by reactive loads like motors or transformers. A PF of 1.0 is a “pure” resistive load (like a heater), while a PF of 0.8 is typical for household electronics.
Real Power (kW) vs. Apparent Power (kVA): kW is the actual energy doing work. kVA is the total energy flowing through the wire. If your power factor is 1.0, then kW = kVA. If the PF is lower, your wires carry more current (Amps) than the kW rating would suggest.
Why use this calculator?
Whether you are sizing a circuit breaker for a new appliance, calculating the load for a portable generator, or monitoring the energy efficiency of industrial machinery, converting Amps to kW is the only way to determine the actual energy cost and power demand of your equipment.