How to use this kVA to kW calculator
- Direction, choose kVA to kW or kW to kVA. The field labels update to match.
- Value, enter your apparent power in kVA or your real power in kW.
- Power factor, enter a value between 0 and 1 (0.8 is a common default).
- Read your result and the power factor used, they update instantly as you type.
Nothing is submitted or stored: the numbers never leave your device, so you can size equipment privately.
kVA, kW and power factor
These two units describe different things. kVA is apparent power, the total power flowing in an AC circuit, while kW is real power, the part that actually does useful work like turning a motor or producing heat. The link between them is the power factor, a number from 0 to 1 that tells you how much of the apparent power is converted into real work.
The two formulas are simple. To go from apparent to real power use kW = kVA × power factor. To go the other way use kVA = kW ÷ power factor. So 100 kVA at a power factor of 0.8 gives 80 kW, and 80 kW at the same 0.8 gives back 100 kVA. When the power factor is 1.0 the two values are equal, which happens with purely resistive loads such as heaters and incandescent lamps.
If you do not know the exact power factor for your system, 0.8 is a typical default for mixed commercial and industrial loads with motors. Equipment nameplates, generators and UPS units often state both a kVA and a kW rating, and the ratio between them is the power factor the manufacturer assumed.
Note: This calculator uses a simple single-figure power factor. Real installations can vary with load, so for generator, transformer or switchgear sizing confirm the figures with the equipment ratings or a qualified electrical engineer.
Frequently asked questions
How do you convert kVA to kW?
Multiply the kVA by the power factor: kW = kVA × power factor. So 100 kVA at a power factor of 0.8 gives 80 kW.
How do you convert kW to kVA?
Divide the kW by the power factor: kVA = kW ÷ power factor. So 80 kW at a power factor of 0.8 gives 100 kVA.
What is the difference between kVA and kW?
kVA is apparent power and kW is real power. Apparent power is the total power in the circuit, real power is the part that does useful work, and the power factor is the ratio between them.
What power factor should I use?
If you are unsure, 0.8 is a common default for mixed and motor loads. Purely resistive loads like heaters sit near 1.0.
Is my data uploaded?
No, everything is calculated on your device and nothing is sent anywhere.