Equipment nameplates often list kVA; your loads consume kW. This guide walks through the kVA to kW converter: apparent power in kVA, power factor as a decimal, and real power in kilowatts.
Benefits
- Core formula: kW = kVA × power factor.
- Separates apparent (kVA) from real (kW) power in AC systems.
- Typical PF ranges for resistive, motor, and mixed loads built in.
How it works
- Enter apparent power in kVA from the generator, UPS, or transformer plate.
- Add power factor (0–1)—0.9 for 90%, 1.0 for resistive loads.
- Read real power in kW—the useful work the source can deliver at that PF.
FAQ
How do I convert kVA to kW?
kW = kVA × PF. Example: 10 kVA at 0.85 power factor → 10 × 0.85 = 8.5 kW real power. At PF 1.0, kVA and kW match; lower PF means less real power for the same apparent rating.
What is a typical power factor?
Resistive heaters and incandescent loads are near 1.0. Induction motors and fluorescent lighting often run 0.7–0.9. Mixed commercial panels may average 0.8–0.95. Use measured PF from a meter when available.
Why does kVA matter if I pay for kW?
Conductors, breakers, and transformers are sized on apparent power (current × voltage), not real power alone. A 10 kVA genset at 0.7 PF delivers only 7 kW—oversizing on kVA without PF check leads to disappointed runtime or tripped breakers.
Technical specifications
- Real power kW = kVA × PF.
- PF = kW ÷ kVA (0–1 for lagging unity).
- Apparent power kVA = kW ÷ PF (reverse check).
- Related: kva-to-kw, inverter-sizing, amps-to-watts, power-factor.
kVA is what the wire sees; kW is what the load uses
Apparent power in volt-amperes includes both real and reactive components in AC circuits. Real power in watts does the actual work—heat, motion, light. Power factor is the ratio between them. A 15 kVA transformer feeding motor loads at 0.8 PF delivers 12 kW, not 15 kW. Converting kVA to kW before budgeting keeps generator and UPS quotes honest.
Nameplate kVA without PF misleads sizing
Portable generators advertise kVA or kW interchangeably in marketing copy. Industrial UPS units state kVA prominently. Enter the plate kVA and your expected load power factor—motor-heavy sites need conservative PF assumptions. Resistive-only campsites can use PF near 1.0. The converter makes the assumption explicit instead of hidden.
PF penalties and infrastructure costs
Utilities sometimes bill large customers for poor power factor because extra apparent current heats conductors without delivering billable kW. Even off-grid, undersized PF means higher current for the same real load—larger cables, warmer breakers. After kW is known, pair results with Amps to Watts or inverter sizing tools for the amp draw at your service voltage.