PhysicsCalcs
Electricity

kW to kVA Calculator

Convert kW to kVA, kVA to kW, calculate power factor, and find apparent power for single-phase and three-phase AC systems.

Interactive calculator

kW to kVA Calculator

Convert kW to kVA, kVA to kW, calculate power factor, and find apparent power for single-phase and three-phase AC systems.

in W or kW

0 to 1 (e.g. 0.85)

Your result will appear here.

Choose a calculation mode, fill in the known values, and click Calculate.

Quick Guide

  • Choose: kW to kVA, kVA to kW, PF, or single/three-phase.
  • Enter real power and power factor.
  • Click Calculate for the conversion.

Table of Contents

Key Takeaways

  • kVA = kW / PF. Apparent power equals real power divided by power factor.
  • Lower power factor means higher kVA for the same kW load.
  • kW to kVA conversion is essential for sizing generators, transformers, and UPS systems.
  • At PF = 1 (unity), kVA and kW are equal.
  • Three-phase apparent power: S = √3 × V_L × I_L.

What Is kW to kVA Conversion?

Converting kW to kVA determines the total apparent power a system must supply to deliver a given real power load. Since generators, transformers, and UPS units are rated in kVA, this conversion is critical for proper equipment sizing.

kW to kVA Infographic

Conversion Formulas

kVA=kWPFkVA = \frac{kW}{PF}

kW to kVA

kW=kVA×PFkW = kVA \times PF

kVA to kW

kW to kVA Conversion Table

kWPF 0.7PF 0.8PF 0.85PF 0.9PF 1.0
1014.312.511.811.110.0
2535.731.329.427.825.0
5071.462.558.855.650.0
100142.9125.0117.6111.1100.0
250357.1312.5294.1277.8250.0
500714.3625.0588.2555.6500.0

How to Use

  1. 1Select a conversion mode.
  2. 2Enter real power (kW) and power factor.
  3. 3Click Calculate.
  4. 4Review apparent power (kVA) and reactive power (kVAr).

Examples

kW to kVA

80 kW, PF = 0.8. kVA = 80/0.8 = 100 kVA.

Generator Sizing

Need 150 kW, PF = 0.85. kVA = 150/0.85 ≈ 176.5 kVA. Choose a 200 kVA generator.

Applications

Generator sizing, UPS selection, transformer specification, cable sizing, switchgear rating, utility billing, and power distribution planning.

Common Mistakes

  • Treating kW and kVA as identical.
  • Using an incorrect power factor assumption.
  • Forgetting the \u221A3 factor for three-phase systems.
  • Not adding a safety margin when sizing equipment.

Accuracy and Limitations

Assumes constant power factor and sinusoidal waveforms. Actual loads may have varying PF and harmonic content. Always apply appropriate derating and safety factors when sizing electrical equipment.

Frequently Asked Questions

Why do I need to convert kW to kVA?›

Generators, transformers, and UPS systems are rated in kVA (apparent power). To properly size this equipment for a kW (real power) load, you must account for the power factor.

How do I convert kW to kVA?›

Divide kW by the power factor: kVA = kW / PF. For example, 80 kW at PF = 0.8 requires 100 kVA.

Why is kVA always higher than kW?›

Because PF ≤ 1, dividing by PF gives a larger number. The difference is the reactive power component.

What is the kW to kVA formula for three-phase?›

First find S (kVA) = √3 × V_L × I_L / 1000, then P (kW) = S × PF, or S = P / PF.

How does this differ from the kVA to kW Calculator?›

They use the same formulas but with different default modes. This tool defaults to kW → kVA conversion, while the kVA to kW Calculator defaults to the reverse.

Sources / References

  1. IEEE Standard 100: Power Definitions
  2. NIST: SI Units
Manish Kumar

Author & technical reviewer

Manish Kumar

PhysicsCalcs tools are reviewed with an educational focus: clear formulas, transparent assumptions, and practical context for students and science learners.

Learn more about Manish