kW to kVA Calculator

Convert Real Power (kW) to Apparent Power (kVA). Determine the true generator size needed for your equipment.

Power Details

kW

Apparent Power

-- kVA

Reactive Power

-- kVAR

Amperage

-- Amps

Power Triangle Visualization

Real (kW) Reactive (kVAR) Apparent (kVA) θ

Common Generator Sizes

Real Power (kW) Apparent Power (kVA) @ 0.8 PF Est. Amps (240V, 1-Phase) Est. Amps (480V, 3-Phase)
10 kW12.5 kVA52 A15 A
20 kW25 kVA104 A30 A
30 kW37.5 kVA156 A45 A
50 kW62.5 kVA260 A75 A
100 kW125 kVA521 A150 A
200 kW250 kVA1042 A300 A

How to Convert kW to kVA

Generators and transformers are often rated in kVA (Apparent Power), while the engines or motors they power are rated in kW (Real Power). To properly size a generator, you must account for the system's inefficiency, represented by the Power Factor (PF).

The Formula

kVA = kW / PF

Where:

  • kW (Kilowatts): Real power doing useful work.
  • PF (Power Factor): Efficiency ratio (0.0 to 1.0). Standard for generators is 0.8.
  • kVA (Kilovolt-Amps): The total load on the generator windings.

Example: You have a 100 kW load with a power factor of 0.8.
Calculation: 100 kW / 0.8 = 125 kVA. You need a 125 kVA generator.

What is Reactive Power (kVAR)?

In the "Power Triangle" visualization above, kVAR is the vertical side. It represents power that bounces back and forth between the source and the load to create magnetic fields (in motors/transformers). It doesn't do "real" work, but the generator still has to supply it.