kVA to kW Calculator (and kW to kVA)
kVA to kW converts apparent power in kilovolt-amperes into real power in kilowatts by multiplying by the power factor: kW equals kVA times PF. The calculator also works in reverse, kW to kVA, and a table of common generator and transformer sizes shows the kW available at power factors from 0.7 to 1.
8 kW P = S × PF → 10 kVA × 0.8 = 8 kW. 10 kVA S = P ÷ PF → 8 kW ÷ 0.8 = 10 kVA.kVA to kW
kW to kVA
How to convert kVA to kW
Apparent power (kVA) is voltage times current. Real power (kW) is the part that does work. The ratio between them is the power factor: kW = kVA × PF, and kVA = kW ÷ PF. Power factor runs from 0 to 1; resistive loads are near 1, and motors are often 0.8 to 0.9.
Worked example: a 10 kVA generator at PF 0.8
10 × 0.8 = 8 kW of real power. If your loads total 9 kW at PF 0.9 they need 9 ÷ 0.9 = 10 kVA, so this generator would be at its limit.
kVA to kW table
| kVA | kW at PF 0.7 | kW at PF 0.8 | kW at PF 0.9 | kW at PF 1.0 |
|---|---|---|---|---|
| 1 | 0.7 | 0.8 | 0.9 | 1 |
| 2 | 1.4 | 1.6 | 1.8 | 2 |
| 3 | 2.1 | 2.4 | 2.7 | 3 |
| 5 | 3.5 | 4 | 4.5 | 5 |
| 7.5 | 5.25 | 6 | 6.75 | 7.5 |
| 10 | 7 | 8 | 9 | 10 |
| 15 | 10.5 | 12 | 13.5 | 15 |
| 20 | 14 | 16 | 18 | 20 |
| 25 | 17.5 | 20 | 22.5 | 25 |
| 30 | 21 | 24 | 27 | 30 |
| 40 | 28 | 32 | 36 | 40 |
| 50 | 35 | 40 | 45 | 50 |
| 75 | 52.5 | 60 | 67.5 | 75 |
| 100 | 70 | 80 | 90 | 100 |
| 150 | 105 | 120 | 135 | 150 |
| 200 | 140 | 160 | 180 | 200 |
Why generators and transformers are rated in kVA
The heating of a transformer or generator depends on current, which follows apparent power, not on how much of it does work. That is why they are rated in kVA while appliances use watts. To find the current from kVA, use kVA to amps; for watts to amps with a power factor, see watts to amps.
Other conversions are on the MicroCoulomb home page.
Frequently asked questions
How do you convert kVA to kW?
Multiply kVA by the power factor: kW = kVA × PF.
How many kW is 10 kVA?
At PF 0.8 it is 8 kW; at PF 0.9 it is 9 kW; at PF 1 it is 10 kW.
How do you convert kW to kVA?
Divide kW by the power factor: kVA = kW ÷ PF.
Which power factor should I use?
Use the value on the nameplate. Without it, 0.8 is a common assumption for generators and motor loads.
Updated