Enter current, voltage, and phase to calculate the apparent power (kVA) a circuit or transformer has to carry.
How to Use the Amps to kVA Calculator
Enter the current in amps and the voltage in volts, then pick Single-Phase or Three-Phase to match the circuit — the result updates as you type, no submit button involved.
kVA measures apparent power: the full electrical load a circuit, transformer, or generator has to be sized for, regardless of how efficiently that load turns electricity into useful work. It's nothing more than voltage times current, scaled down to kilo-units.
Single-phase: kVA = (V × I) ÷ 1000
Three-phase: kVA = (√3 × V × I) ÷ 1000230V and 10A single-phase comes out to 2.3 kVA. Feed the same two numbers into the three-phase formula and it climbs to about 3.98 kVA — the √3 factor (roughly 1.732) accounts for a third conductor carrying current offset in phase from the other two, not some separate physical effect worth memorizing on its own.
There's no power factor field on this page, and that's deliberate. Apparent power only cares about the raw voltage-current product a conductor or winding has to carry — it says nothing about how much of that ends up doing useful work. That's precisely why transformer and generator nameplates get rated in kVA rather than kW: the equipment has to handle the full current no matter what's plugged into it downstream, so its rating can't depend on a power factor that changes from one connected load to the next.
Need the portion that actually does work rather than just what the circuit carries? That's real power, measured in kW, and it does need a power factor — see the Amps to kW calculator for that version of this same relationship.