KW to Amps Calculator
Convert kilowatts to amps for single phase, three phase, and DC circuits. Enter kW and voltage for an instant result with formula transparency.
Circuit Type
Enter Values
Typical: 0.8 (motors), 0.9 (general), 1.0 (resistive)
Result (Amps)
Quick Reference (PF=0.9)
| kW | @120V | @240V | @480V 3ph |
|---|---|---|---|
| 1 kW | 9.26A | 4.63A | 1.39A |
| 2 kW | 18.52A | 9.26A | 2.78A |
| 5 kW | 46.3A | 23.1A | 6.94A |
| 10 kW | 92.6A | 46.3A | 13.9A |
| 20 kW | - | 92.6A | 27.8A |
kW to Amps Quick Reference (PF = 0.9)
| Power (kW) | 120V Single Ph | 240V Single Ph | 208V 3-Phase | 480V 3-Phase |
|---|---|---|---|---|
| 1 kW | 9.26 A | 4.63 A | 3.13 A | 1.39 A |
| 2 kW | 18.5 A | 9.26 A | 6.25 A | 2.78 A |
| 5 kW | 46.3 A | 23.1 A | 15.6 A | 6.94 A |
| 10 kW | 92.6* A | 46.3 A | 31.3 A | 13.9 A |
| 20 kW | - A | 92.6 A | 62.5 A | 27.8 A |
| 50 kW | - A | - A | 156 A | 69.4 A |
* Impractical at 120V for high loads - use 240V or 3-phase
Understanding the kW to Amps Conversion
Kilowatts (kW) measure real electrical power - the actual energy consumed or produced by a device. Amperes (amps or A) measure electrical current - the flow of electrons through a circuit. These two quantities are related by voltage and, for AC circuits, by power factor. Understanding this relationship is essential for electrical sizing, generator selection, and circuit design.
The fundamental relationship is Ohm's Law combined with power equations. For a DC circuit or a purely resistive AC load, Power (watts) = Voltage x Current, so Current = Power / Voltage. For AC circuits with reactive loads (motors, transformers, capacitors), the power factor accounts for the phase difference between voltage and current waveforms, making the actual current draw higher than the "real power" alone would suggest.
Why Three Phase Requires Less Current
Three phase power is more efficient than single phase for the same power delivery. The square root of 3 factor (1.732) in the three-phase formula means you can deliver the same power with significantly less current per conductor. For example, a 10 kW load at 240V single phase requires 46.3 amps, while the same 10 kW at 480V three phase requires only 13.9 amps - a 70% reduction in current. This directly translates to smaller wire sizes and reduced installation costs.
This is why large industrial motors, HVAC compressors, and manufacturing equipment use three-phase power. The reduced current for the same power means lower resistive losses in conductors, smaller wire and conduit sizes, and lower electrical infrastructure costs. Three-phase power also delivers more even power transfer compared to the pulsing nature of single-phase.
Power Factor Correction
In industrial applications, low power factor can be costly. Utilities often charge demand penalties for power factors below 0.95, and low PF means your conductors and equipment must be sized larger to handle the higher apparent current. Power factor correction capacitors can be added to motor circuits to bring PF closer to 1.0, reducing current draw and improving efficiency. Our calculator lets you input the actual power factor to accurately predict current requirements for any scenario.