kVA、kW、安培換算

How to use this calculator

1. Choose single-phase or three-phase.
2. Select which value you know — kVA, kW or amps — and enter it.
3. Enter the voltage (line-to-line for 3-phase) and the power factor.
4. Click Convert to get the other two values.

The formulas

Real and apparent power are linked by the power factor: kW = kVA × PF and kVA = kW ÷ PF. Apparent power and current depend on the number of phases — single-phase: kVA = V × A ÷ 1000; three-phase: kVA = √3 × V × A ÷ 1000, where V is the line-to-line voltage and √3 ≈ 1.732.

kVA vs kW

kVA is apparent power, the total the source must supply; kW is real power, the part that does useful work. Their ratio is the power factor. Resistive loads have PF ≈ 1 (kW = kVA); motors and other inductive loads have PF below 1, so they draw more kVA than kW.

Quick reference: kVA to amps

常見問題

How do I convert kVA to kW?

Multiply by the power factor: kW = kVA × PF. For example, 10 kVA at PF 0.9 is 9 kW.

How do I convert kW to amps?

First convert kW to kVA (kVA = kW ÷ PF), then amps = kVA × 1000 ÷ V (single-phase) or ÷ (√3 × V) for three-phase.

What is the difference between kVA and kW?

kVA is apparent power (total supplied); kW is real power (useful work). They are equal only when the power factor is 1.

Why use √3 for three-phase?

In a balanced three-phase system the √3 (≈1.732) factor relates the line-to-line voltage to the per-phase quantities, so total power = √3 × V × I × PF.