Convert Volt-Ampere to Kilowatt (VA → kW)

Converting volt-amperes to kilowatts is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in volt-amperes

   Start with the number of volt-amperes (VA) you want to convert.
2. 2
   Multiply by 0.001

   The conversion factor from VA to kW is 0.001. Multiply your value by this number.
3. 3
   Read the result in kilowatts

   The result is your value in kilowatts (kW).

Multiply the value in volt-amperes by 0.001. For the reverse direction, multiply by 1,000.

• ✓VA = V × A (RMS).
• ✓For purely resistive loads, VA = W.
• ✓For motors, computers: VA > W (power factor < 1).

• ✗Treating VA and W as identical — only true for resistive loads.
• ✗Buying UPS by W when VA rating is required.
• ✗Ignoring power factor in transformer sizing.

What is the Volt-Ampere?

The volt-ampere (VA) is the SI unit of apparent power in alternating-current (AC) electrical systems. Equal to volts times amperes, the VA represents the magnitude of power flowing in an AC circuit before accounting for the phase relationship between voltage and current. For purely resistive loads (incandescent bulbs, heaters), 1 VA = 1 W. For reactive loads (motors, transformers, fluorescent lights), the apparent power (VA) is larger than the real power (W) because of the phase shift — the ratio is the 'power factor.' Transformers, UPS units, and generators are rated in VA or kVA (kilo-VA) because they must handle the apparent power, not just the real power. A typical home UPS for a desktop computer is 600–1,500 VA. The VA relates to the watt (1 VA = 1 W only at unity power factor), the kilovolt-ampere (1 kVA = 1,000 VA), and the megavolt-ampere (1 MVA = 10⁶ VA — used in utility-scale transformers).

• Transformer sizing
• Uninterruptible power supply (UPS) ratings
• Generator capacity

What is the Kilowatt?

The kilowatt equals 1,000 watts and is the standard power rating for European cars, household appliances, and small industrial motors. European car engines are rated in kW (a typical economy car has 70–110 kW, a sports car 200–500 kW), even though horsepower is often quoted alongside for marketing. Major household appliances range from 1–3 kW (electric kettle, microwave) to 5–10 kW (electric oven, central air conditioning). Solar panel arrays for homes are sized in kW (typical residential system: 5–10 kW). Electric motors in industry are commonly rated 1 to 500 kW. The kilowatt relates to the watt (1,000 W = 1 kW), the megawatt (1,000 kW = 1 MW), horsepower (1 kW ≈ 1.341 hp), the BTU per hour (1 kW ≈ 3,412 BTU/h), and the kWh of energy when multiplied by hours.

• Car and motorcycle engine ratings (Europe)
• Home electrical service sizing
• HVAC and heating-pump capacity