kW to Amps Calculator

The cable, the breaker, and the protection device that feed any piece of plant are all sized in amps, but the kit is bought and specified in kW. A 22 kW DC rapid EV charger draws roughly 32 amps on a 400 V three-phase supply at unity power factor, and the upstream protection has to allow for inrush, harmonic content, and the diversity of whatever else is on the same distribution board. Get the conversion wrong and the install either nuisance-trips or sits oversized for years.

On commercial sites with multiple chillers, compressors, or banks of chargers, the cumulative current draw at peak is what drives the LV switchgear sizing and the agreed capacity with the network operator. A 250 kW chiller plus a 200 kW heat pump retrofit plus a 150 kW EV charger bank does not need a 600 kW supply if the diversity factor is right, but it certainly will if every load is sized in isolation. The conversion between kW and amps, with the right assumptions about three-phase, power factor, and voltage, is how that diversity calculation gets honest.

Purely Energy supports clients planning electrification projects where the combined load shape determines both the engineering scope and the contract design. The conversation usually starts with the equipment nameplates, ends with a capacity strategy that the DNO accepts, and runs through a half-hourly demand audit in the middle. The free converter here is step one of that workflow. For multi-site operators, the conversion gets repeated across every location in the estate, with the answers feeding the capital plan, the contract renewals calendar, and the SECR reporting line for the year ahead.