kVA to amps calculator
Useful when sizing a generator or transformer, or checking that cables and breakers can carry the full-load current.
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How to use it
- Enter phases, apparent power and voltage.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Single-phase: I = kVA × 1000 ÷ V. Three-phase: I = kVA × 1000 ÷ (√3 × V) with V the line voltage.
Example
Inputs: Phases = Three-phase, Apparent power = 100 kVA, Voltage = 400 V. Result: Full-load current: 144.34 A; Real power at PF 0.8: 80 kW.
Limits and caveats
- Assumes a load balanced across the three phases.
- Real power is shown at a power factor of 0.8, the usual generator rating basis; your load may differ.
Questions about this tool
Why are generators rated in kVA?
Winding heat depends on total current whatever the power factor. Real power in kW equals kVA × PF.
How many amps does a 1000 kVA transformer give at 11 kV?
About 52.5 A on the 11 kV side. On the 400 V side it is about 1443 A.
Which voltage do I enter for three-phase?
The line-to-line voltage, such as 400 or 415 V, not the phase-to-neutral voltage.