kVA Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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Small changes can matter a lot in kva. Electromagnetic calculations are easiest to audit when voltage, current, field, charge, frequency, and geometry are kept in their correct roles. Use the calculator as a transparent first model, then decide whether your real system needs a more detailed treatment.

What this calculator does

Use this page to evaluate apparent power from Voltage (V), Current (I), Apparent power (S). The result is most useful when the entered quantities describe one consistent physical setup and the displayed units stay attached to the number.

How to use it

Use measured, specified, or deliberately hypothetical values for Voltage (V), Current (I), Apparent power (S), Power factor, Real power. Set Load distribution to match the solve path you want. Keep the quantity definitions and unit prefixes exactly as labeled; a correct number in the wrong physical quantity or prefix will still produce a misleading result.

How the calculation works

Apparent power is S = kVI, where k is 1 for single phase and √3 for three phase. The page reports kVA = S/1000 and real power P = S·PF.

Example

For 230 V, 10 A, single-phase power, apparent power is 2,300 VA = 2.3 kVA. At power factor 0.8, the corresponding real power is 1,840 W. Three-phase selection would introduce the √3 factor.

How to interpret the result

Read the apparent power with its sign, magnitude, phase, frequency, geometry, and unit as applicable. A field, reactance, power factor, loss, or flux value should be compared only with a quantity defined in the same way.

Limitations and notes

Real electrical and magnetic systems can add parasitics, finite geometry, temperature dependence, nonlinear materials, frequency-dependent losses, tolerances, and measurement uncertainty beyond the ideal relationship shown here. Pay particular attention to Voltage (V), Current (I) and their units. A mathematically correct result can still be incomplete when the real system includes effects not represented on the form.