Use this calculator to convert between kW (real power) and kVA (apparent power) using power factor (PF).
What does “kW en kVA” mean?
“kW en kVA” simply means “kW and kVA.” In electrical systems, these two units describe different types of power. They are related, but not the same. If you size a generator, transformer, inverter, or UPS, understanding both is essential.
Quick Definitions
kW (Kilowatts)
kW is real power: the useful power that actually does work, such as turning motors, heating elements, or lighting equipment.
kVA (Kilovolt-Amps)
kVA is apparent power: the total power supplied, including both useful power and reactive power. Utilities and equipment nameplates often use kVA ratings.
Power Factor (PF)
Power factor is the ratio between real power and apparent power:
- PF = kW / kVA
- PF ranges from 0 to 1
- A PF closer to 1 means power is being used more efficiently
Core Formulas
- kVA = kW ÷ PF
- kW = kVA × PF
The calculator above uses exactly these formulas, so you can switch conversion direction instantly.
When to Convert kW to kVA
You usually convert kW to kVA when selecting electrical infrastructure. A machine may list its demand in kW, but your generator or transformer might be rated in kVA.
- Sizing standby generators for buildings
- Choosing transformer capacity for industrial loads
- Checking UPS compatibility for IT racks
When to Convert kVA to kW
You convert kVA to kW when you need to know usable output power. For example, a generator may be advertised as 100 kVA, but your available real power depends on PF.
Example Calculations
Example 1: Convert 120 kW to kVA at PF 0.8
kVA = 120 ÷ 0.8 = 150 kVA
Example 2: Convert 250 kVA to kW at PF 0.9
kW = 250 × 0.9 = 225 kW
Typical Power Factor Ranges
- Resistive loads (heaters, incandescent lighting): PF near 1.0
- Motors and inductive loads: PF often 0.7 to 0.9
- Mixed commercial buildings: PF commonly around 0.85 to 0.95
Common Mistakes to Avoid
- Using PF = 1 for all equipment
- Confusing kW and kWh (power vs energy)
- Sizing equipment with no safety margin
- Ignoring low PF penalties in utility billing
Practical Tips for Engineers and Technicians
1. Check nameplate ratings first
Nameplates often provide kW, kVA, PF, voltage, and current. Use manufacturer data whenever possible instead of assumptions.
2. Use realistic PF values
For preliminary estimates, PF = 0.8 is common, but always verify against actual operating conditions.
3. Plan margin
Add headroom for startup currents, expansion, and ambient condition effects. A design that is too tight can fail in real operation.
FAQ
Is kVA always bigger than kW?
Usually yes, unless PF = 1. Because kW = kVA × PF, and PF is at most 1, kW cannot exceed kVA.
Can I improve power factor?
Yes. Facilities often install capacitor banks or active correction systems to increase PF and reduce losses or penalties.
Why do generators use kVA ratings?
Generator alternators are limited by current and voltage, which align naturally with apparent power (kVA).
Final Thoughts
A reliable kW and kVA conversion is one of the most useful quick checks in electrical design and operations. Use the calculator at the top of this page whenever you need fast, accurate conversions with power factor included.