Amps measure current and kilowatts measure power — converting between them needs the voltage, and for AC circuits, the power factor and number of phases. Get the formula wrong and your sizing for cables, generators or solar can be badly off.
This calculator applies the right equation automatically: DC is simply V × I, single-phase AC multiplies by power factor, and three-phase AC also multiplies by √3. Enter your values for an instant, accurate result.
Frequently asked questions
What's the formula for amps to kW?
DC: kW = V × A ÷ 1000. Single-phase AC: kW = PF × V × A ÷ 1000. Three-phase AC: kW = √3 × PF × V × A ÷ 1000.
What is power factor?
It's the ratio of real power to apparent power in an AC circuit (0–1). Resistive loads are near 1; motors are often around 0.8.
Why does three-phase use √3?
Because the three phases are offset by 120°, the line-to-line relationship introduces a factor of the square root of three (≈1.732).