kVA to Amps Calculator
Enter power as kVA, kW or hp and get the current for single or three-phase, with the kW/kVA conversion made explicit and the formulas documented.
Last updated: 2026-09-15
How the calculation works
- kVA input is used directly; kW and hp are first converted to kVA through the power factor (hp at 746 W each).
- Single-phase divides kVA by voltage; three-phase divides by √3 times voltage.
- The result also shows real and apparent power so the PF conversion is visible.
Formula
Single-phase: I = kVA × 1000 / V Three-phase: I = kVA × 1000 / (√3 × V) kW → kVA: kVA = kW / PF hp → kVA: kVA = hp × 0.746 / PF
| Symbol | Meaning | Unit |
|---|---|---|
I | Line current | A |
S | Apparent power | kVA |
V | Line-to-line voltage | V |
PF | Power factor | — |
Worked example
Interpreting the result
The result is the line current a balanced load draws at steady state. Use it for breaker sizing (with the applicable code multipliers), transformer loading checks and generator sizing. For motors, prefer nameplate FLA or NEC tables — the conversion here assumes the entered power is the electrical input.
Assumptions
- Balanced three-phase load, sinusoidal conditions.
- hp values are mechanical output power converted at 746 W per hp with the entered power factor.
Limitations
- Does not include motor inrush, harmonics or unbalance.
- Transformers are sized by kVA, but their actual loading also depends on the load's power factor.
Frequently asked questions
How many amps is 10 kVA at 240 V single-phase?
10,000 / 240 = 41.7 A. At 480 V three-phase it would be 1000 / (1.732 × 480) = 12.0 A.
Why does power factor matter?
kW is the real work; kVA is what the wires must carry. At PF 0.8, delivering 8 kW requires 10 kVA of current capacity. Low PF therefore increases conductor and breaker sizes for the same useful power.