Convert kVA to Amps quickly with our online calculator. Supports both single-phase and three-phase electrical systems. Includes conversion formulas, tables, and technical guides.
How to Convert kVA to Amps
To convert kVA (Kilovolt-Amps) to Amps (Current), you need to know the system’s voltage and whether it is a single-phase or three-phase circuit. Because kVA represents apparent power, the calculation involves moving from a power rating back to the electrical current flowing through the conductors.
The Formula
For Single-Phase (1φ) Systems:
Amps = (kVA × 1,000) ÷ Volts
For Three-Phase (3φ) Systems:
Amps = (kVA × 1,000) ÷ (Volts × 1.732)
*The constant 1.732 represents the square root of 3 ($\sqrt{3}$), which accounts for the phase displacement in three-phase power.
kVA to Amps Reference Table
This table shows the current (Amps) required for various kVA ratings at common industrial voltages:
| kVA Rating | 120V (1φ) | 240V (1φ) | 480V (3φ) |
|---|---|---|---|
| 5 kVA | 41.67 A | 20.83 A | 6.01 A |
| 10 kVA | 83.33 A | 41.67 A | 12.03 A |
| 30 kVA | 250.0 A | 125.0 A | 36.08 A |
| 100 kVA | 833.3 A | 416.7 A | 120.3 A |
Contextual Information
Why do we convert kVA to Amps?
Generators, transformers, and UPS systems are almost always rated in kVA. However, circuit breakers, fuses, and electrical wires are rated in Amps. To ensure an electrical installation is safe, you must convert the power source’s kVA rating into Amps to choose the correctly sized protective equipment and cable gauge.
The Role of Voltage
As you can see from the reference table, increasing the voltage significantly decreases the amperage for the same amount of kVA. This is why high-powered industrial machines use higher voltages (like 480V) rather than standard household voltages; it allows for much thinner (and cheaper) wiring to carry the same amount of power.
Important Note: “Real” Power vs. “Apparent” Power
Remember that kVA is Apparent Power. If you are converting from kW (Real Power), you must also factor in the Power Factor of the load. This calculator assumes you are working with the apparent power rating. For most backup power scenarios, calculating for kVA ensures the most conservative and safest amperage estimate.