VA to kVA Calculator
VA to kVA Calculation Formula
The apparent power S in kilovolt-amps (kVA) is equal to the apparent power S in volt-amps (VA), divided by 1000:
S(kVA) = S(VA) / 1000
Understanding VA to kVA Conversion
What is Apparent Power?
Apparent power, measured in volt-amps (VA) or kilovolt-amps (kVA), represents the total power in an AC electrical circuit:
- Combination of real power (watts) and reactive power (VAR)
- Product of voltage and current in a circuit
- Important for sizing electrical equipment and wiring
The conversion to kVA is simply a matter of scaling (dividing by 1000) since both VA and kVA measure apparent power.
When to Use VA vs. kVA
| Measurement | Typical Applications | Scale |
|---|---|---|
| VA (Volt-Amps) | Small appliances, electronics, residential circuits | 1 VA = 1 volt × 1 amp |
| kVA (Kilovolt-Amps) | Industrial equipment, transformers, generators, large UPS systems | 1 kVA = 1000 VA |
Why kVA is Important
kVA ratings are crucial for:
- Transformer sizing: Transformers are rated in kVA
- Generator capacity: Standby generators often use kVA ratings
- Industrial equipment: Large motors and machinery specifications
- Electrical distribution: Utility companies use kVA for capacity planning
Conversion Examples
| Equipment | VA Rating | kVA Equivalent |
|---|---|---|
| Small UPS | 1,500 VA | 1.5 kVA |
| Commercial transformer | 25,000 VA | 25 kVA |
| Industrial motor | 7,500 VA | 7.5 kVA |
| Data center PDU | 20,000 VA | 20 kVA |
Relationship Between VA, kVA, and Power Factor
While VA to kVA is a simple scaling conversion, power factor relates apparent power (VA/kVA) to real power (watts/kW):
Real Power (W) = Apparent Power (VA) × Power Factor
This means:
- For resistive loads (PF=1): 1 kVA = 1 kW
- For inductive loads (PF=0.8): 1 kVA = 0.8 kW
- Equipment must be sized for kVA, but energy is consumed in kW
Frequently Asked Questions
Q: Is VA the same as watts?
A: No, VA (apparent power) and watts (real power) are only equal when power factor is 1 (purely resistive loads). For other loads, VA will be higher than watts.
Q: Why do transformers use kVA instead of kW ratings?
A: Transformers must handle the full apparent power (current × voltage) regardless of power factor, so they're rated in kVA which accounts for both real and reactive power.
Q: How do I convert kVA back to VA?
A: Simply multiply the kVA value by 1000. For example, 5 kVA = 5 × 1000 = 5000 VA.
Q: When would I need to use this VA to kVA conversion?
A: You'll need this conversion when working with equipment specifications (like UPS systems or transformers) that use different units, or when scaling up from small (VA) to large (kVA) power calculations.