Amps to kW Calculator

Multiply √3 by the line-to-line voltage, the line current and the power factor, then divide by 1000: P = √3 × V × I × cos φ / 1000. 32 A at 400 V and a power factor of 0.8 is about 17.7 kW.

Multiply the voltage, the current and the power factor, then divide by 1000: P = V × I × cos φ / 1000. 32 A at 230 V is 7.36 kW at unity power factor, or 5.89 kW at 0.8.

A 32 A, 400 V three-phase supply delivers 22.2 kVA, which is 22.2 kW for a resistive load or about 17.7 kW at a power factor of 0.8. That is the capacity at full current; the usable load also depends on the protection and the maximum demand.

kVA is the apparent power, voltage times current, and sets the heating in cables and transformers. kW is the real power that does work. The power factor is the ratio kW / kVA, so for a resistive load they are equal.

For three-phase use the line-to-line voltage (400 V in Australia and New Zealand) with the line current; the √3 in the formula accounts for the three phases. For single-phase use the phase-to-neutral voltage (230 V).

It gives the current. Multiply by the voltage and, for AC, the power factor. Without a power analyser the power factor is an estimate, so the result is the apparent power in kVA at best and the kW is approximate.