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Choose single-phase or three-phase, enter the voltage and the kVA (or the amps for the other direction). kVA is apparent power, so no power factor is needed for this conversion.

Enter your values

Pick what you know and what you want to find.
Generators and transformers above a few kVA are usually three-phase.
Where do I find this?

The nameplate shows 1~ or 1-phase for single-phase, 3~ or 3-phase for three-phase.

Three-phase: the voltage between two phases (400 V, 480 V, 208 V). Single-phase: 230 V or 120/240 V.
Where do I find this?

The nameplate of the generator, transformer or supply states the voltage.

From the nameplate, in kVA.
Where do I find this?

Generators, transformers and UPS units are rated in kVA. 1 kVA = 1000 VA.

Result

Enter your values to see the result.

Current per phase
– A
Apparent power
– VA

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How it is calculated

  • Single-phase: amps = kVA × 1000 ÷ volts
  • Three-phase: amps = kVA × 1000 ÷ (√3 × volts)
  • Amps to kVA: kVA = volts × amps ÷ 1000 (× √3 for three-phase)

Example

A 10 kVA three-phase generator at 400 V supplies up to 10 × 1000 ÷ (1.732 × 400) ≈ 14.4 A per phase. A 10 kVA single-phase unit at 230 V supplies about 43.5 A.

What this estimate leaves out

The result is the full-load current. Motors draw much more when they start, and cables and breakers need margins and local rules. Ask a qualified electrician before sizing them.

Written and reviewed by QLines, Cologne · Last reviewed

FAQ

Frequently Asked Questions

How do you convert kVA to amps?

Single-phase: amps = kVA × 1000 ÷ volts. Three-phase: amps = kVA × 1000 ÷ (1.732 × volts). Example: 10 kVA at 400 V three-phase is about 14.4 A.

What is the difference between kVA and kW?

kVA is apparent power (volts × amps); kW is the real power that does work. kW = kVA × power factor. The kVA to kW calculator converts between them.

How many amps is a 100 kVA transformer?

At 400 V three-phase about 144 A per phase; at 480 V about 120 A.

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