Electrical & Lighting · Conversion · Free

VA to kW Calculator

Convert apparent power in volt-amps (VA) to real power in kilowatts (kW). Enter the apparent power in volt-amps and the power factor, and press Calculate to get the real power in kilowatts. Everything runs locally in your browser.

STEP 1

Enter volt-amps

Type the apparent power S in volt-amps (VA) — the volt-amp rating you see on inverters, UPS units and generators. Zero is allowed; negative values are rejected because apparent power is a magnitude.

STEP 2

Enter the power factor

Type the power factor PF as a number between 0 and 1: 1 for resistive loads, around 0.8 for typical mixed or motor loads, or the exact value from the device datasheet.

STEP 3

Press Calculate, read kilowatts

The result appears in kilowatts (kW): P(kW) = S(VA) × PF / 1000. Press Reset at any time to clear the fields and start over.

VA to kW calculation

How do you convert VA to kW?: The real power P in kilowatts (kW) is equal to the apparent power S in volt-amps (VA), times the power factor PF, divided by 1000: P(kW) = S(VA) × PF / 1000. For example, 1200 VA at a power factor of 0.8 gives 1200 × 0.8 / 1000 = 0.96 kW.
What is the power factor?: The power factor is the ratio of real power (kW) to apparent power (kVA), always between 0 and 1. Resistive loads such as heaters and incandescent lamps have PF ≈ 1; motors, transformers and switching power supplies sit lower, typically 0.6 to 0.95. Without the power factor you cannot turn VA into kW — that is why this calculator asks for it.
Why is kW smaller than kVA?: Apparent power (VA, kVA) is volts times amps as drawn from the supply; real power (W, kW) is what the load actually consumes. On reactive loads part of the current sloshes back and forth without doing work, so kW = kVA × PF is at most equal to kVA — and only equal when PF = 1.
Worked examples: A 3000 VA UPS feeding loads at PF 0.8 delivers 3000 × 0.8 / 1000 = 2.4 kW. A 2400 VA server at PF 0.7 uses 1.68 kW. A 5000 VA generator at near-unity PF 0.95 supplies 4.75 kW. At PF 0 (purely reactive) the real power is 0 kW.
What if I know kW and want VA?: Use the reverse relation S(VA) = P(kW) × 1000 / PF. Enter the known kW value together with the same power factor into a kW to VA calculator, or rearrange this page’s formula directly.

Privacy: every calculation runs in your browser tab — no value you type is sent anywhere, and this tool does not use the clipboard, storage, or the network. Results assume a constant power factor; verify real installations with a power meter.