kVA to kW Converter
Use this calculator to convert apparent power (kVA) into real power (kW) using power factor.
What does kVA in kW mean?
If you are sizing generators, UPS systems, transformers, or electrical loads, you will often see power listed in kVA rather than kW. These two numbers are related but not identical.
- kVA (kilovolt-amps) = apparent power (total electrical power supplied)
- kW (kilowatts) = real power (useful power actually doing work)
The missing piece is the power factor (PF), which tells you how effectively apparent power is converted into useful output power.
kVA to kW formula
Because power factor is between 0 and 1, real power (kW) is usually lower than apparent power (kVA). For many purely resistive loads (like electric heaters), PF is close to 1. For motors and inductive loads, PF can be lower.
How to use this calculator
- Enter your apparent power in kVA.
- Enter your power factor (for example: 0.8, 0.9, or 0.95).
- Click Calculate kW.
- Read the converted real power value in kW.
Quick examples
| kVA | Power Factor | kW Result |
|---|---|---|
| 50 | 0.80 | 40.00 |
| 100 | 0.90 | 90.00 |
| 250 | 0.95 | 237.50 |
| 500 | 1.00 | 500.00 |
Common power factor values by load type
- Incandescent heating loads: 0.95 to 1.00
- Induction motors (lightly loaded): 0.60 to 0.75
- Induction motors (well loaded): 0.80 to 0.90
- Data centers with correction: 0.90 to 0.99
- Modern UPS systems: often close to 1.00
Why kVA matters for equipment sizing
Utilities and equipment manufacturers often rate systems in kVA because electrical infrastructure must carry both real and reactive components of power. A generator may have enough kVA capacity, but if your power factor is low, the available kW output can be significantly less than expected.
In practical terms, using the correct PF in your kVA-to-kW conversion helps avoid:
- Undersized generators and nuisance trips
- Overheating in cables and transformers
- Poor energy efficiency and higher operating cost
Related formulas you may need
kW to kVA
Single-phase apparent power from voltage and current
Three-phase apparent power from voltage and current
Once you calculate kVA from voltage/current, you can use this page to convert that value into kW.
FAQ
Can kW ever be greater than kVA?
No. Since PF cannot exceed 1, kW is always less than or equal to kVA.
What if I do not know the power factor?
Check equipment nameplates, technical datasheets, or utility power quality data. If no value is available, engineers often estimate with a conservative PF (such as 0.8) and refine later.
Is this calculator accurate for generator sizing?
It is accurate for the conversion itself. For final generator selection, also consider starting current, harmonics, transient loads, altitude, ambient temperature, and duty cycle.