kVA Calculator
Calculate kVA, kW, and amperage for single-phase and three-phase electrical systems. Enter any two values to find the third — useful for generator sizing and transformer selection.
14.43 A
How to use the kva calculator
Enter apparent power (kVA), line voltage, and phase configuration.
Formula & explanation
Single phase: I = (kVA × 1000) / V. Three phase: I = (kVA × 1000) / (√3 × V_line).
Examples
10 kVA @ 400 V three-phase ≈ 14.43 A.
Frequently asked questions
- What is kVA and how does it differ from kW?
- kVA is apparent power (voltage × current), while kW is real power actually consumed. They are related by kW = kVA × power factor.
- Why does three-phase use √3 in the formula?
- In a balanced three-phase system the line voltage is √3 times the phase voltage. The √3 factor accounts for this geometric relationship between the three phases.
- When do I need to calculate current from kVA?
- Generator sizing, transformer capacity, and breaker/cable selection are all rated in kVA. Converting to amps lets you verify that wiring and protective devices are correctly rated.
Related electrical & electronics tools
- Capacitor Calculator — Series & Parallel CapacitanceCalculate equivalent capacitance for capacitors in series and parallel, plus RC time constants. Enter values, get total capacitance instantly — free, no signup.
- Power CalculatorCalculate electrical power in watts from any two of voltage, current, or resistance. Uses P = VI, P = V²/R, and P = I²R — useful for circuit design and energy estimation.
- Ohm's Law CalculatorSolve Ohm's Law (V = IR) for voltage, current, or resistance — enter any two values to find the third. Also calculates power (W) from the known values.
- Voltage DividerCalculate the output voltage of a two-resistor voltage divider. Enter input voltage and both resistor values — useful for sensor biasing, ADC reference voltages, and signal conditioning.
- Inductance CalculatorCalculate inductive reactance (XL) and energy stored in an inductor from inductance and frequency. Also computes resonant frequency for LC circuits.
- Decibel CalculatorCalculate decibels (dB) from voltage ratios, power ratios, or amplitude ratios — and convert dB values back to linear ratios. Covers dBV, dBm, and dBW standards.