kVA to kW calculator
Real power in kilowatts equals apparent power in kilovolt-amperes times the power factor. Choose the direction, enter the value and the power factor, and the calculator gives the converted value and the reactive power.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Choose kVA to kW or kW to kVA.
- Enter the power and the power factor. Check the nameplate; 0.8 is shown as a default only.
- Read the converted power and the reactive power.
kW = kVA × PF. kVA = kW ÷ PF. kvar = kVA × √(1 − PF²).
Worked example
A generator rated 10 kVA with a load at power factor 0.8 can deliver 10 × 0.8 = 8 kW of real power. The reactive power is 10 × √(1 − 0.64) = 6 kvar.
Tips
- At a power factor of 1, kVA and kW are equal.
- A generator or UPS rating in kVA does not tell you the kW unless you know the power factor of the load.
Frequently asked questions
How do you convert kVA to kW?
Multiply kVA by the power factor. kW = kVA × PF. At a power factor of 0.8, 10 kVA is 8 kW.
How do you convert kW to kVA?
Divide kW by the power factor. kVA = kW ÷ PF. 8 kW at a power factor of 0.8 needs 10 kVA.
What is power factor?
It is the ratio of real power to apparent power, a number between 0 and 1. Resistive loads such as heaters are close to 1; motors and transformers are lower because part of the current only moves energy back and forth.
What is kvar?
Reactive power, the part of the apparent power that does no useful work. The three are related by kVA² = kW² + kvar², so kvar = kVA × √(1 − PF²). For 10 kVA at 0.8 this is 6 kvar.
Does it matter whether the supply is single-phase or three-phase?
Not for this conversion. The relation between kVA, kW and power factor is the same. Phase count matters only when you derive current from kVA, which this tool does not do.