kVA to kW Calculator

Written byOleh Soloninupdated 25 September 2026

Direction

Value

Power factor

Result

Real power, kW8
Apparent power, kVA10
Reactive, kVAr6
Current at 220 V, A45.45
Current at 380 V, A15.19
Power factor used0.8
WorkingP = S × cos φ = 10 × 0.8 = 8 kW; Q = √(S² − P²) = 6 kVAr

The difference between what is drawn and what works

Links apparent and real power through the power factor and shows the resulting current at both 220 and 380 volts.

Apparent power in kilovolt-amperes is voltage times current, S = V × I. Real power in kilowatts is the part that becomes heat, light and work: P = S × power factor. With sinusoidal voltage and current the rest is reactive power Q, and the three form a right triangle: S² = P² + Q². With harmonics √(S² − P²) also includes distortion, not only reactive power.

That is why a 10 kVA load draws 8 kW of real power at a power factor of 0.8 and 9.5 kW at 0.95. The current is the same in both cases, because apparent power sets it. A generator's plate carries two limits, kVA and kW, and the load must stay within both: a 10 kVA / 8 kW set will not deliver 9.5 kW just because the load's power factor is 0.95.

How to use

Choose the direction: kVA to kW or kW to kVA.
Enter the power and the power factor from the equipment's rating plate.
Read the other power, the reactive power and the current at 220 V single-phase and 380 V three-phase.

10, 20, 50 and 100 kVA at different power factors

Each row is a separate run. The three-phase current is the line current, S ÷ (√3 × 380 V).

All rows come from the calculator on this page.
Apparent, kVA	Power factor	Real, kW	Reactive, kVAr	Current at 220 V	Current at 380 V
10	0.8	8	6	45.45 A	15.19 A
10	0.9	9	4.359	45.45 A	15.19 A
10	0.95	9.5	3.122	45.45 A	15.19 A
20	0.8	16	12	90.91 A	30.39 A
50	0.8	40	30	227.27 A	75.97 A
100	0.8	80	60	454.55 A	151.93 A

What this calculator shows

Real and apparent power side by side
The reactive component in kVAr
The current that power produces at 220 and at 380 volts

What to keep in mind

Currents are shown for 220 V single-phase and 380 V between phases, as in Russia's older ratings; at 230/400 V they are slightly lower.

FAQs

How many kW are in 1 kVA?

As many as the power factor: 0.8 kW at 0.8, exactly 1 kW at 1. Without the power factor there is no converting kVA to kW.

What power factor should I use if I don't know it?

The one on the rating plate. The 0.8 in the calculator is an example, not a standard; IEC 60364-5-52 also uses 0.8 when nothing better is known, but only for voltage-drop sums.

What is reactive power?

Power that shuttles back and forth between source and load without doing work, while still loading the cables with current. With sinusoidal voltage and current Q = √(S² − P²): 10 kVA and 8 kW leave 6 kVAr.

What current does a 10 kVA load draw?

On 220 V single-phase, 10,000 ÷ 220 = 45.45 A; on 380 V three-phase, 10,000 ÷ (1.732 × 380) = 15.19 A in each phase.

Why does kVA matter more than kW for a generator?

Current heats the windings, and apparent power sets the current. A 10 kVA generator feeding a load at a power factor of 0.8 delivers 8 kW — and is fully loaded doing it.

How do I convert kW to kVA?

Divide by the power factor: 5 kW at 0.9 is 5.556 kVA, 8 kW at 0.8 is 10 kVA.

Worked example

A 10 kVA generator

Input: 10 kVA at a power factor of 0.8

Output: 8 kW real and 6 kVAr reactive power

Note: The current on a 220 V single-phase supply is 45.45 A — the same as 10 kW at a power factor of 1 would draw.

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kVA to kW Calculator

Result

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