What is the kVA to Amps Calculator?
This tool converts apparent power, measured in kilovolt-amperes (kVA), into electrical current, measured in amperes (A). It supports both single-phase and three-phase electrical systems, making it useful for sizing generators, transformers, cables, breakers, and UPS systems. Because kVA represents apparent power rather than real power, no power factor is needed for this conversion.
How to use it
Select whether your system is single phase or three phase. Enter the apparent power in kVA and the system voltage in volts. For three-phase systems, use the line-to-line voltage (for example 400 V or 415 V). Click calculate to see the resulting current in amperes.
The formula explained
For a single-phase system the current is the apparent power in volt-amperes divided by the voltage: $$I = \frac{\text{kVA} \times 1000}{V}$$ For a three-phase system the line current uses the square root of three: $$I = \frac{\text{kVA} \times 1000}{\sqrt{3} \times V}$$ The factor of 1000 converts kilovolt-amperes to volt-amperes, and \(\sqrt{3} \approx 1.732\) accounts for the relationship between line and phase quantities in a balanced three-phase load.
Worked example
Suppose you have a 50 kVA three-phase transformer at 400 V. The current is $$I = \frac{50 \times 1000}{1.732 \times 400} = \frac{50000}{692.8} \approx 72.2 \text{ A}$$ For a 10 kVA single-phase load at 240 V, $$I = \frac{10 \times 1000}{240} \approx 41.67 \text{ A}$$
FAQ
Do I need power factor? No. kVA is apparent power, so the conversion to amps depends only on voltage. You would need power factor only when converting between kVA and kW.
Which voltage do I use for three phase? Use the line-to-line (phase-to-phase) voltage, such as 400 V or 480 V.
Why is there a \(\sqrt{3}\) for three phase? In a balanced three-phase system, total apparent power equals \(\sqrt{3}\) times line voltage times line current, so solving for current introduces the \(\sqrt{3}\) factor.
