Amps to kW Calculator
Convert amperes (current) to kilowatts (power) using voltage. This calculator supports DC, single-phase AC, and three-phase AC power systems. The formula is kW = (Amps x Volts) / 1000.
How to Convert Amps to kW
- Multiply the current in amps by the voltage in volts to get watts.
- For AC circuits, also multiply by the power factor.
- For three-phase AC, multiply by sqrt(3) (approximately 1.732).
- Divide the result by 1000 to convert watts to kilowatts.
Formula
DC: kW = (Amps x Volts) / 1000
AC (single-phase): kW = (Amps x Volts x PF) / 1000
AC (three-phase): kW = (sqrt(3) x Amps x Volts x PF) / 1000
Example Calculation
Convert 20 amps at 240V DC to kW:
kW = (20 x 240) / 1000 = 4800 / 1000 = 4.8 kW
Convert 30A at 480V three-phase AC (PF = 0.9):
kW = (1.732 x 30 x 480 x 0.9) / 1000 = 22,447 / 1000 = 22.45 kW
Amps to kW Reference Table (DC)
| Current | Voltage | Power |
|---|---|---|
| 5A | 120V | 0.60 kW |
| 10A | 120V | 1.20 kW |
| 15A | 120V | 1.80 kW |
| 20A | 120V | 2.40 kW |
| 10A | 240V | 2.40 kW |
| 20A | 240V | 4.80 kW |
| 30A | 240V | 7.20 kW |
| 50A | 240V | 12.00 kW |
| 100A | 240V | 24.00 kW |
Frequently Asked Questions
How many kW is 30 amps at 240V?
30 amps at 240V DC equals 7.2 kW (30 x 240 / 1000 = 7.2 kW).
Can I convert amps to kW without knowing voltage?
No. Power depends on both current and voltage. You must know the voltage to calculate kilowatts from amps.
What is the difference between kW and kVA?
kW is real power (does actual work), while kVA is apparent power (includes reactive power). They are related by: kW = kVA x Power Factor.
How do I determine the power factor of my load?
Check the equipment nameplate or specifications. Resistive loads (heaters) have PF near 1.0. Inductive loads (motors) typically have PF of 0.7-0.9. A power meter can measure actual PF.
Is a 200 amp service enough for a house?
A 200A service at 240V provides 48 kW of capacity. This is sufficient for most homes, including those with electric heating, AC, and an EV charger.