kW ⇄ kVA Converter
Convert Real Power to Apparent Power.
About the kW to kVA Calculator
This kW to kVA calculator converts real power (kW) into apparent power (kVA) using power factor. Generators, transformers, and UPS systems are rated in kVA but typically specified by the kW load they need to support — this calculator bridges the two so you can size equipment correctly.
Default power factor is 0.8 for mixed industrial loads. Adjust based on your specific application: motors typically run at 0.8–0.95, modern electronics at 0.95–1.0, fluorescent lighting at 0.5–0.9, and resistive heaters at 1.0.
How kW to kVA conversion works
The relationship between real and apparent power:
kVA = kW ÷ Power Factor
Real power (kW) is what does useful work — turns motor shafts, lights filaments, generates heat. Apparent power (kVA) is total current times voltage. Reactive power (kVAR) is the difference, which circulates between source and load without doing work but still loads the equipment that has to carry it.
Worked example
A facility runs a 50 kW industrial load at 0.8 power factor. Required generator size: kVA = 50 ÷ 0.8 = 62.5 kVA. Round up to a standard 65 or 75 kVA generator. If the same load runs at unity power factor (1.0), only 50 kVA would be needed — which is why power factor correction can reduce generator and transformer sizing.
Power factor by load type
- Resistive loads (heaters, incandescent lights, electric ovens): PF = 1.0
- Modern electronics with active PFC (computers, servers, modern LED drivers): PF = 0.95–1.0
- Industrial motors at full load: PF = 0.85–0.92
- Industrial motors at light load: PF = 0.50–0.75 (drops significantly below 50% load)
- Fluorescent lighting (older magnetic ballast): PF = 0.5–0.9
- VFD-driven motors (input side): PF = 0.95–1.0 typically
- Welders, induction furnaces: PF = 0.5–0.7
When to use this calculator
- Sizing a backup generator for a facility load specified in kW
- Selecting transformer ratings for new electrical service installations
- Specifying UPS systems for data centers and other critical loads
- Calculating utility demand charges (which are kVA-based for many commercial tariffs)
- Matching switchgear ampacity to actual load conditions
- Planning power factor correction projects (knowing how much kVAR to add)
- Estimating utility-rebate savings from PF improvement programs
Frequently Asked Questions
How do you convert kW to kVA?
Divide kilowatts by power factor: kVA = kW ÷ PF. For 50 kW at 0.8 PF: kVA = 50 ÷ 0.8 = 62.5 kVA. Lower power factor means higher kVA for the same kW.
What is power factor?
Power factor (PF, range 0–1) is the ratio of real power (kW) to apparent power (kVA). Mathematically PF = cos(φ), where φ is the phase angle between voltage and current. PF of 1.0 means current and voltage are perfectly in phase; PF of 0.7 means significant phase lag from inductive loads.
Why is kVA always larger than kW?
Because kVA includes both real power (which does work) and reactive power (which circulates between source and load). Only resistive loads at PF = 1.0 have kVA equal to kW. Most real loads have some inductance or capacitance, making PF less than 1.
What power factor should I assume if I don’t know the actual value?
For mixed industrial loads, 0.8 is a common default. For pure resistive loads (heaters, incandescent lights), use 1.0. For motor-heavy facilities, use 0.85. When in doubt, size conservatively at 0.8 — it’s better to have generator headroom than to undersize.
Why are generators rated in kVA?
A generator’s thermal limit is set by current (apparent power), not by load PF. The windings heat up based on amps, regardless of whether the current is in or out of phase with voltage. Sizing in kVA ensures the generator can deliver full current capacity at any power factor.
Can I improve power factor to reduce kVA?
Yes — install power factor correction capacitors. They cancel out the inductive reactive power from motors, raising PF closer to 1.0. This reduces kVA demand, can lower utility bills (especially under kVA-based tariffs), and frees up transformer capacity. Payback is typically 12–36 months for facilities with PF below 0.85.
Are kVA and kVAR the same?
No. kVA is apparent power (total). kW is real power (useful work). kVAR is reactive power (circulating). They form a right triangle: kVA² = kW² + kVAR². PF correction reduces kVAR, which shrinks kVA toward kW.
kW to kVA Conversion Table
Apparent power (kVA) depends on power factor. The table below shows common kW loads converted to kVA at three typical power factors. Use the calculator above for your exact power factor.
| Real Power | kVA at 0.8 PF | kVA at 0.9 PF | kVA at 1.0 PF |
|---|---|---|---|
| 5 kW | 6.3 kVA | 5.6 kVA | 5.0 kVA |
| 10 kW | 12.5 kVA | 11.1 kVA | 10.0 kVA |
| 15 kW | 18.8 kVA | 16.7 kVA | 15.0 kVA |
| 20 kW | 25.0 kVA | 22.2 kVA | 20.0 kVA |
| 25 kW | 31.3 kVA | 27.8 kVA | 25.0 kVA |
| 30 kW | 37.5 kVA | 33.3 kVA | 30.0 kVA |
| 37 kW | 46.3 kVA | 41.1 kVA | 37.0 kVA |
| 50 kW | 62.5 kVA | 55.6 kVA | 50.0 kVA |
| 75 kW | 93.8 kVA | 83.3 kVA | 75.0 kVA |
| 100 kW | 125.0 kVA | 111.1 kVA | 100.0 kVA |
| 150 kW | 187.5 kVA | 166.7 kVA | 150.0 kVA |
| 200 kW | 250.0 kVA | 222.2 kVA | 200.0 kVA |
Common kW to kVA Questions
How do you convert kW to kVA?
Divide the real power (kW) by the power factor: kVA = kW ÷ PF. For example, 50 kW at 0.8 power factor = 50 ÷ 0.8 = 62.5 kVA.
What is 100 kW in kVA?
At 0.8 power factor, 100 kW = 125 kVA. At 0.9 PF it is 111.1 kVA, and at unity (1.0) PF it equals 100 kVA. Generators and transformers are rated in kVA, so always size in kVA.
Why is kVA higher than kW?
kVA (apparent power) includes both the real power that does work and the reactive power drawn by inductive loads like motors. The lower the power factor, the larger the gap between kVA and kW.
Related calculators and Electracore products
Sizing equipment after your conversion? Browse our General Purpose motor stock from Baldor, WEG, and Marathon.
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