Formula & Calculator
kW to kVA Conversion
Converts real power in kW to apparent power in kVA using the power factor.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| kVA | Apparent power | kVA |
| kW | Real power | kW |
| cos θ | Power factor | dimensionless |
What it means
The conversion from real power (kW) to apparent power (kVA) is kVA = kW / cosθ, where cosθ is the power factor. This is used to size transformers, cables, and generators based on the real power requirement and the expected power factor. A lower power factor requires a larger kVA rating for a given kW. Example: A motor with a 8 kW load and a power factor of 0.8 requires a generator rated at 8/0.8 = 10 kVA. This ensures that the generator can handle the current drawn by the motor, which is higher than for a resistive load of the same wattage.
Worked example
kW to kVA – Practical Example
Real‑World| Parameter | Value |
|---|---|
| kW | 8 |
| cos θ | 0.8 |
| Formula | kVA = kW / cos θ |
Common mistakes
Watch for unit mismatches (W vs kW, single- vs three-phase) and remember to include power factor or efficiency where the formula requires it.Applications
kW to kVA conversion kVA = kW / cosθ converts real power back to apparent power. This is used to determine the required apparent power rating of equipment for a given real power. Engineers use it to select transformers and cables. This conversion is essential when power factor is known.
- Determination of apparent power for equipment sizing
- Power factor correction and system design
- Feeder and transformer capacity calculation
- Load analysis and planning
- Educational understanding of power factor