kVA to Amps Calculator

Enter apparent power (kVA), voltage, and phase to calculate the current a load draws.

How to Use the kVA to Amps Calculator

Apparent power in kVA and voltage in volts go in; set the phase toggle to match the supply, and current comes out. Nothing else to configure.

This is the sizing question in reverse: instead of measuring current and asking what load it represents, you already know the load — a nameplate rating, a transformer spec, a panel schedule — and need the current it draws so you can pick a breaker, a cable gauge, or a feeder.

Single-phase: I = (kVA × 1000) ÷ V
Three-phase:  I = (kVA × 1000) ÷ (√3 × V)

A 5 kVA single-phase load at 230V draws about 21.7A. Put the same 5 kVA on a three-phase 230V supply instead and current drops to roughly 12.6A per conductor — three phases are sharing the job that one phase carried alone, so each one moves less current for the same total apparent power. That's the practical reason three-phase distribution shows up anywhere power demand gets large: lower current per conductor for the same delivered load means thinner, cheaper cable.

Whatever number comes out, it's still apparent current, not a final breaker size — a real installation adds a safety margin (commonly 125% of continuous load, per most electrical codes) on top of this raw figure before picking hardware. Treat this calculator's output as the starting point for that sizing exercise, not the finished spec.

Voltage matters just as much as phase count here, and it's the field most likely to be wrong on a first try. A 5 kVA load pulls very different current at 120V than it does at 230V or 400V — check the actual supply voltage on the panel or nameplate rather than assuming a default.