Convert apparent power in kilovolt-amperes into watts of real power using the load power factor.
Starting from an apparent-power rating instead? Use the main kVA to kW converter for any power factor.
Every diagram and table on this page updates with the calculator above.
Scale to volt-amperes first, then apply the power factor.
A 5 kVA supply at 0.9 power factor delivers 4,500 watts. The remaining 500 VA of capacity is reactive — real current in the conductors, but no useful output at the other end.
The three are not interchangeable and cannot simply be added. Watts and VAR combine as the sides of a right triangle whose hypotenuse is the VA figure.
Real and reactive power are perpendicular. That is why you cannot subtract one from the other — a 5 kVA supply carrying 4,500 W has 2,179 VAR left over, not 500.
The Pythagorean relationship that makes the arithmetic behave unintuitively.
Subtracting watts from volt-amperes to find VAR gives the wrong answer every time. Use the square root: VAR = √(VA² − W²).
Small-equipment ratings converted at your chosen power factor.
| kVA | Real power (W) | Reactive power (VAR) |
|---|---|---|
| 0.5 kVA | 450 | 217.94 |
| 1 kVA | 900 | 435.89 |
| 1.5 kVA | 1,350 | 653.83 |
| 2 kVA | 1,800 | 871.78 |
| 3 kVA | 2,700 | 1,307.7 |
| 5 kVA | 4,500 | 2,179.4 |
| 7.5 kVA | 6,750 | 3,269.2 |
| 10 kVA | 9,000 | 4,358.9 |
| 15 kVA | 13,500 | 6,538.3 |
| 20 kVA | 18,000 | 8,717.8 |
| 30 kVA | 27,000 | 13,076.7 |
| 50 kVA | 45,000 | 21,794.5 |
| 100 kVA | 90,000 | 43,589 |
| 200 kVA | 180,000 | 87,178 |
When a supplier quotes kVA but your specification is in watts, this grid answers the question directly. The spread across a row is exactly the uncertainty introduced by an unknown power factor.
| kVA | 0.7 PF | 0.8 PF | 0.9 PF | 0.95 PF | 1 PF |
|---|---|---|---|---|---|
| 1 kVA | 700 | 800 | 900 | 950 | 1,000 |
| 2 kVA | 1,400 | 1,600 | 1,800 | 1,900 | 2,000 |
| 5 kVA | 3,500 | 4,000 | 4,500 | 4,750 | 5,000 |
| 10 kVA | 7,000 | 8,000 | 9,000 | 9,500 | 10,000 |
| 20 kVA | 14,000 | 16,000 | 18,000 | 19,000 | 20,000 |
| 50 kVA | 35,000 | 40,000 | 45,000 | 47,500 | 50,000 |
| 100 kVA | 70,000 | 80,000 | 90,000 | 95,000 | 100,000 |
In a server room or plant room the distinction becomes a hardware decision. Breakers and busbars are sized from volt-amperes; air conditioning is sized from watts, because only real power ends up as heat in the room.
Protect for 20 kVA of current but cool for 19 kW of heat.
29 calculators built on the same maths as the tool above. Each one has its own inputs, interactive diagrams and worked examples.
Common questions about converting kva to watts.