Amps to kVA Calculator
Convert current in amps (A) to apparent power in kilovolt-amps (kVA). Select single phase or three phase — for three phase, choose line to line or line to neutral voltage — enter the amps and volts, and press Calculate to get kVA. Everything runs locally in your browser.
Select the phase number
Pick "Single phase" for a single AC circuit, or "Three phase" for a three-phase system. For three phase, also choose the voltage type: line to line (between two phases) or line to neutral (phase to neutral/ground).
Enter amps and volts
Type the phase current in amps (A) and the RMS voltage in volts (V). Both values must be zero or higher — zero is valid here because none of the formulas divides by a measured value.
Press Calculate, read kVA
The apparent power appears in kilovolt-amps (kVA), rounded to at most three decimals. Copy the result to your clipboard, or press Reset to clear everything and start over.
Amps to kVA formulas
- Single phase amps to kVA calculation formula
- The apparent power S in kilovolt-amps is equal to current I in amps, times the voltage V in volts, divided by 1000: S(kVA) = I(A) × V(V) / 1000. For example, 10 A at 120 V gives 10 × 120 / 1000 = 1.2 kVA.
- 3 phase amps to kVA formula — line to line voltage
- The apparent power S in kilovolt-amps is equal to phase current I in amps, times the line to line RMS voltage VL-L in volts, divided by 1000: S(kVA) = √3 × I(A) × VL-L(V) / 1000. For example, 10 A at 400 V line to line gives √3 × 10 × 400 / 1000 ≈ 6.928 kVA.
- 3 phase amps to kVA formula — line to neutral voltage
- The apparent power S in kilovolt-amps is equal to phase current I in amps, times the line to neutral RMS voltage VL-N in volts, divided by 1000: S(kVA) = 3 × I(A) × VL-N(V) / 1000. For example, 5 A at 230 V line to neutral gives 3 × 5 × 230 / 1000 = 3.45 kVA.
- Which voltage type should I pick for three phase?
- Use line to line when your voltage is measured between two phases (e.g. 400 V in EU, 208/480 V in US commercial systems); use line to neutral when it is measured from one phase to neutral (e.g. 230 V in EU, 120 V in US). The two agree when VL-L = √3 × VL-N, which is exactly how balanced wye systems are defined: 3 × 230 = √3 × (√3 × 230) = 690.
- Why does the voltage type not matter in single phase?
- A single-phase circuit has one pair of conductors, so there is no line-to-line versus line-to-neutral distinction — the formula is always S(kVA) = I(A) × V(V) / 1000, with no √3 or 3× factor. The voltage-type selector applies only when "Three phase" is selected.
- kVA vs kW — what is apparent power?
- kVA is apparent power: the product of RMS voltage and current, without the power factor. Real power in kilowatts is P(kW) = S(kVA) × PF. A 6.928 kVA three-phase load at a power factor of 0.8 does 6.928 × 0.8 ≈ 5.54 kW of real work. Use a power factor calculator to convert between the two.
Privacy: every calculation runs in your browser tab — no value you type is sent anywhere. Copy result uses your clipboard only. Results assume balanced sinusoidal RMS values; verify real installations with a multimeter.