kW to Amps Calculator
This kW to amps calculator converts power in kilowatts to current in amps using the supply voltage. Enter the kilowatts and the volts and the kW to amps calculator returns the current, because the conversion of kilowatts to amps depends on voltage and, for AC, power factor. It handles DC, single phase, and three phase, so you can find amps from kW for any circuit.
Results
The kW to Amps Calculator is part of our AC & Three Phase collection. Browse more ac & three phase to size, convert, and check your work alongside this tool.
What the kW to amps calculator does
Kilowatts measure power and amps measure current, and voltage links the two, so the conversion of kilowatts to amps is never a fixed number. This kW to amps calculator takes the power and the supply voltage and returns the current. It runs the kw to ampere calculation for DC, single phase, and three phase, and it reverses too, so the same tool covers amperes to kilowatts when you already know the current.
The kw to ampere calculation
For DC the kw to ampere calculation divides power by voltage:
Single-phase AC adds power factor, and three phase adds the √3 factor:
The factor of 1000 converts kilowatts to watts first. This is why the conversion kilowatts to amps always needs voltage, and why the kW to amps calculator asks for it before it can find amps from kW.
kW to amps calculator example
A 10 kW three-phase motor at 400 V with a 0.9 power factor. The kw to ampere calculation is:
The same 10 kW on a 230 V single phase supply draws about 48 A, which shows how the conversion of kilowatts to amps swings with voltage and phase. Enter your values and the kW to amps calculator returns the current.
How to use the kW to amps calculator
Enter the power in kilowatts and the supply voltage, then choose DC, single phase, or three phase. For AC, add the power factor. The kW to amps calculator multiplies out the kw to ampere calculation and returns the current in amps. To find amps from kW on a motor, use its rated voltage and power factor; the conversion kilowatts to amps then matches the nameplate current closely.
Reading the kW to amps calculator result
The current tells you what the wiring, breaker, and contactor must handle. Compare it against the cable ampacity and the protective device rating, because a load pulling more amps than the circuit allows will trip or overheat. Motors draw more than the steady figure at startup, so size for inrush as well. The kW to amps calculator gives the running current from the kw to ampere calculation; add a margin before you pick the breaker.
When to use the kW to amps calculator
- Sizing a breaker for a motor with the conversion kilowatts to amps
- Checking generator and inverter output when you find amps from kW
- Converting a nameplate rating with the amp to kilowatt converter
- Planning three-phase distribution using the kw to ampere calculation
Common kw to amps calculator mistakes
- Wrong circuit type. DC, single phase, and three phase each change the kw to ampere calculation; pick the right one.
- Ignoring power factor. For motors, the conversion kilowatts to amps needs the real PF or it underestimates current.
- Forgetting inrush. Size protection above the running current the kW to amps calculator returns.
Tips for accurate results
- Use the nameplate voltage and power factor when you find amps from kW.
- Select the correct phase so the kw to ampere calculation matches your supply.
- Add a starting margin before sizing the breaker from the conversion kilowatts to amps.
Why the conversion kilowatts to amps depends on the circuit
The conversion kilowatts to amps looks like one sum but really has three forms, and picking the wrong one is the usual mistake. DC is simplest: current is power over voltage. Single-phase AC divides by voltage times power factor, because real loads draw current that is partly out of step with the voltage. Three phase adds the √3 factor, since the three conductors share the load and each carries less current than a single-phase circuit would for the same power. The kW to amps calculator selects the right form once you choose the circuit type, so the kw to ampere calculation matches reality rather than a textbook ideal.
Sizing protection after you find amps from kW
Finding the running current is only the start. Motors pull a large inrush current at startup, often several times the running figure, so the breaker and contactor must tolerate that surge without tripping while still protecting the cable. This is why an amp to kilowatt converter used in reverse, or a conversion kilowatts to amps done carelessly, can undersize a circuit. Use the kW to amps calculator for the steady current, then apply the motor starting factor and local code before selecting protection. Pair the result with a wire size check so the conductor carries both the running load and the startup surge.
kW to amps conversion table
Current for common motor sizes at 400 V three phase, power factor 0.9, a quick kw to amps conversion table:
| Power (kW) | Amps at 230 V (1φ) | Amps at 400 V (3φ) |
|---|---|---|
| 1 | 4.8 | 1.6 |
| 5 | 24.2 | 8.0 |
| 10 | 48.3 | 16.0 |
| 15 | 72.5 | 24.1 |
| 22 | 106.3 | 35.3 |
kW to Amps Calculator FAQ
How do I convert kW to amps?
Divide kilowatts by voltage and multiply by 1000, adding power factor and √3 for AC and three phase. The kW to amps calculator runs this kw to ampere calculation for your circuit type.
Why does the conversion need voltage?
Power is voltage times current, so the same kilowatts draw different amps at different voltages. That is why the conversion kilowatts to amps always asks for the supply voltage.
Can it convert amperes to kilowatts?
Yes. The same relationship reverses, so the tool handles amperes to kilowatts and works as an amp to kilowatt converter when you enter the current instead.
What power factor should I use?
Use the motor nameplate value, often 0.8 to 0.9. A lower power factor raises the current the kw to ampere calculation returns, so use the real figure when you find amps from kW.