kW to Amps Calculator
Convert kilowatts to amperes for AC and DC electrical systems
kW to Amps Calculator
Compliant with IEC 60034 Standards
Results:
Current (Amps): 0.00
Power (Watts): 0.00
Formula Used: -
How to Use the kW to Amps Calculator
AC Single Phase
- Select "AC" as system type
- Choose "Single Phase" configuration
- Enter power in kilowatts (kW)
- Input line-to-neutral voltage
- Set appropriate power factor (0.8-1.0)
- Click "Calculate Amps" for results
Common voltages: 120V, 240V (residential)
AC Three Phase
- Select "AC" as system type
- Choose three-phase configuration
- Enter power in kilowatts (kW)
- Input line-to-line or line-to-neutral voltage
- Set power factor based on load type
- Calculate to get current per phase
Common voltages: 208V, 240V, 480V, 600V (industrial)
DC Systems
- Select "DC" as system type
- Enter power in kilowatts (kW)
- Input DC voltage
- Power factor automatically set to 1.0
- Calculate for direct current
Common in solar, battery, and automotive systems
How to Calculate kW to Amps
Understanding the Conversion
AC Single Phase Formula
A = 1000 × kW / (PF × V)
Where:
- A = Current in amperes
- kW = Power in kilowatts
- PF = Power factor (0-1)
- V = Voltage (line-to-neutral)
AC Three Phase Formulas
Line-to-Line: A = 1000 × kW / (√3 × PF × V)
Line-to-Neutral: A = 1000 × kW / (3 × PF × V)
Three-phase systems are more efficient for high-power applications
DC Formula
I = 1000 × P / V
DC calculations are simpler as there's no power factor or phase considerations
Detailed Calculation Example
Example: 10 kW motor on 480V three-phase system with 0.85 power factor
Given:
- Power (P) = 10 kW
- Voltage (V) = 480V (line-to-line)
- Power Factor (PF) = 0.85
- System = Three-phase AC
Calculation:
Using formula: A = 1000 × kW / (√3 × PF × V)
A = 1000 × 10 / (√3 × 0.85 × 480)
A = 10,000 / (1.732 × 0.85 × 480)
A = 10,000 / 706.632
A = 14.15 Amps per phase
Frequently Asked Questions
What is the difference between line-to-line and line-to-neutral voltage?
Line-to-line voltage is measured between any two phases in a three-phase system, while line-to-neutral voltage is measured between any phase and the neutral conductor. Line-to-line voltage is √3 times higher than line-to-neutral voltage in a balanced three-phase system.
How do I determine the correct power factor for my calculation?
Power factor depends on the load type: Resistive loads (heaters, incandescent lights) = 1.0, Inductive loads (motors, transformers) = 0.7-0.9, Capacitive loads = leading power factor. Check equipment nameplates or use typical values: motors 0.8-0.85, fluorescent lighting 0.9, LED lighting 0.9-0.95.
Why is the current different for single-phase vs three-phase systems?
Three-phase systems distribute power across three conductors, reducing the current per conductor compared to single-phase systems of the same power. This is why three-phase is preferred for high-power applications - it requires smaller conductors and is more efficient.
Can I use this calculator for motor starting current?
No, this calculator determines running current based on rated power. Motor starting current (inrush current) is typically 5-7 times higher than running current and requires separate calculations. Use motor starting current tables or consult manufacturer specifications.
What safety factors should I consider when sizing conductors?
Always apply appropriate safety factors and follow electrical codes. The National Electrical Code (NEC) requires conductors to be sized at 125% of continuous loads. Consider voltage drop, ambient temperature, and conductor bundling. Consult a qualified electrician for actual installations.