Enter current, voltage, and phase to calculate the apparent power (kVA) a circuit or transformer has to carry.
How to Use the Amps to Kilovolt-Amps (kVA) Calculator
Current and voltage are the only two numbers this needs; toggle Single-Phase or Three-Phase to match the circuit and the apparent-power reading tracks both fields live.
Single-phase: kVA = (V × I) ÷ 1000
Three-phase: kVA = (√3 × V × I) ÷ 1000A 120V, 20A residential circuit comes out to 2.4 kVA. The same 20A on a 208V three-phase commercial feed — a common US commercial voltage — climbs to about 7.2 kVA, since three-phase power stacks the contribution of all three conductors rather than relying on one.
The reason this exact tool also lives under the shorter Amps to kVA Calculator name: apparent power sizing questions come from two different directions in practice. An electrician staring at a clamp-meter reading and a panel schedule searches for "amps to kVA." A facilities planner cross-checking a UPS or generator spec sheet against a known circuit tends to search "kVA conversion" instead. Same math, same result, different door in.
No power factor field appears here on purpose — apparent power is just the raw voltage-current product, full stop, regardless of how much of it does useful work downstream. If the goal is the portion that's actually usable, the Amps to Kilowatts (kW) calculator adds power factor into the same current and voltage inputs.