Physics

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kVA to Amperage Calculator.

Calculate single-phase RMS current from apparent power and voltage.

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01

Set your values

Results update as you type.

Current: 10 A

Current

0.000000A

Results update automatically as you type.

Use Cases

Sizing circuit breakers and wires

Determine the current draw of single-phase equipment to select appropriate breaker and wire sizes.

Example: A 10 kVA load at 230 V draws 43.48 A, so you'd need a breaker rated above that.

Checking generator or transformer capacity

Verify that a single-phase generator or transformer can handle the current demand of connected loads.

Example: If you have a 15 kVA generator at 120 V, it can supply up to 125 A.

Frequently Asked Questions

How do I convert kVA to amps for a single-phase circuit?
Use the formula: Amps = (kVA × 1000) / Voltage. For example, 5 kVA at 240 V gives 5000 / 240 = 20.83 A. This calculator does that for you.
What is the difference between kVA and kW?
kVA is apparent power (voltage × current), while kW is real power (kVA × power factor). This calculator uses kVA, not kW, so it gives the current based on apparent power.
Can I use this calculator for three-phase systems?
No, this calculator is specifically for single-phase circuits. For three-phase, the formula differs (amps = kVA × 1000 / (√3 × voltage)).

Tips & Common Mistakes

Tips

  • Ensure the voltage you enter is the RMS voltage (the standard measurement for AC circuits).
  • For accurate results, use the actual operating voltage, not the nominal voltage, if it differs.
  • Remember that this calculator assumes a purely resistive load (power factor = 1). For inductive loads, the actual current may be higher.

Common Mistakes to Avoid

  • Forgetting to convert kVA to VA (multiply by 1000) before dividing by voltage.
  • Using peak voltage instead of RMS voltage, which would give incorrect current values.
  • Applying the single-phase formula to three-phase systems without adjusting for the square root of three.

Last updated: August 13, 2026