kW to kVA
Converter
Convert between real power (kW), apparent power (kVA), and power factor. Enter any two values to calculate the third — essential for correctly sizing transformers to your load.
Converting Between Real and Apparent Power
Find the real power (kW) from your equipment nameplate, load schedule, or energy study. This is the actual energy your load consumes and converts to work or heat.
Use the load's nameplate power factor, or consult the typical values table below. If unknown, use 0.80 (80%) for a conservative sizing estimate. Enter power factor as a percentage (e.g., 85 for 0.85).
kVA = kW ÷ Power Factor. The result is the apparent power that your transformer must supply. Select the next standard transformer size above this value.
Size your transformer at 125% of the calculated kVA minimum (divide by 0.8) to allow for load growth, starting currents, and to preserve transformer life.
| Load Type | Typical PF |
|---|---|
| Resistive Heating | 1.00 (100%) |
| LED Lighting | 0.90 – 0.95 |
| Office / Commercial | 0.85 – 0.90 |
| Induction Motors (loaded) | 0.80 – 0.90 |
| Data Centre UPS | 0.90 – 0.95 |
| Variable Frequency Drives | 0.95 – 0.98 |
| Induction Motors (lightly loaded) | 0.50 – 0.70 |
kW (kilowatts) measures real power — the actual energy consumed and converted to work or heat. kVA (kilovolt-amperes) measures apparent power — the total electrical power supplied, including both real and reactive components. The ratio between them is the power factor: kW = kVA × PF.
Power factor (PF) is a dimensionless number between 0 and 1 (or 0% to 100%) expressing the efficiency with which electrical power is converted to useful work. PF = 1.0 (100%) means all supplied power is real power. Motors, transformers, and inductive loads have lagging power factors, typically 0.80 to 0.95. Capacitive loads lead. Unity (1.0) is ideal.
Transformers are rated in kVA (apparent power), not kW (real power). This is because transformer losses and heating depend on the total current flowing through the windings, regardless of whether the load is absorbing real or reactive power. To correctly size a transformer, you must convert your kW load to kVA using the load's power factor.
For motor loads, a power factor of 0.85 is a commonly used conservative assumption. For data centre UPS systems, power factors of 0.90 to 0.95 are typical. For resistive heating loads, power factor is 1.0. If power factor is unknown, assume 0.80 (80%) to provide a conservative kVA estimate.
Enter any two values — leave the one you want to solve blank.
Know Your kVA? Let's Spec the Transformer.
Once you have your kVA requirement and voltage specifications, our engineers can provide a full transformer specification and lead time the same day.