kW to kVA Calculator

Q: How do I convert kW to kVA?

kVA = kW ÷ Power Factor. For example, 8 kW at PF=0.8 requires a 10 kVA generator or UPS.

Q: Why do I need to convert kW to kVA?

Generators, transformers, and UPS systems are rated in kVA. Your load is measured in kW. To select the right equipment, convert your kW load to kVA using your load power factor.

Q: How many kVA is 5 kW at PF 0.8?

kVA = 5 ÷ 0.8 = 6.25 kVA. You would need at least a 6.25 kVA (or the next standard size, 7.5 kVA) generator.

Convert real power (kW) to apparent power (kVA) for selecting generators, UPS systems, and transformers. Includes power factor input for accuracy.

Convert kW to kVA

Real Power (kW)

Power Factor (0–1)

Result

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Apparent Power (kVA)

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Apparent Power (VA)

Formula

kVA = kW ÷ Power Factor

The kVA rating must always be equal to or greater than the required kW divided by the power factor. This is the minimum apparent power your supply must handle.

Example Calculation

Your office has 6 kW of equipment with an average power factor of 0.85. What size UPS do you need?

kVA = 6 ÷ 0.85 = 7.06 kVA
Choose the next standard size: 7.5 kVA or 10 kVA UPS

Adding a 20–25% safety margin is recommended: 7.06 × 1.25 = 8.8 kVA → choose a 10 kVA unit.

Generator & UPS Sizing Rule

Always select equipment rated above your calculated kVA (round up to next standard size).
Add 20–25% safety margin for future load growth and surge capacity.
Generator standard kVA ratings: 5, 7.5, 10, 12.5, 15, 20, 30, 40, 50 kVA and above.
UPS standard VA ratings: 500, 750, 1000, 1500, 2000, 3000, 5000, 6000, 10000 VA.
Transformers are always rated in kVA — never in kW.

Frequently Asked Questions

How do I convert kW to kVA?

Divide kW by the power factor: kVA = kW ÷ PF. If your total load is 10 kW with PF=0.85, you need at least 11.76 kVA (10 ÷ 0.85). Always round up to the next available equipment size.

Why do I need to convert kW to kVA?

Generators, transformers, and UPS units are rated in kVA (apparent power), but your loads are measured in kW (real power). The difference is due to reactive power from inductive loads. Without converting, you risk undersizing your equipment.

How many kVA is 5 kW at PF 0.8?

kVA = 5 ÷ 0.8 = 6.25 kVA. You'd select a 7.5 kVA generator to have safety margin. At PF=1.0 (purely resistive), kVA equals kW exactly — you'd only need a 5 kVA unit.