kVA to kW Calculator – Free Online Tool

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About this calculator

kVA (apparent power) is what a generator, transformer or UPS is rated in; kW (real power) is what actually does useful work. This calculator converts between them using the load's power factor — essential when sizing a generator or transformer for a given real-power load.

Formula

kW = kVA × PF

kVAApparent power — kilovolt-amperes
PFPower factor — 0–1
kWReal power — kilowatts

Worked Example

Given: A 100 kVA DG set supplies a load bank at 0.85 power factor.

Result: kW = 100 × 0.85 = 85 kW of real power available.

How to Use

Enter the apparent power rating in kVA.
Enter the expected power factor of the connected load.
Click Calculate to get the real power in kW.

Important Assumptions

Assumes a single aggregate power factor for all connected loads.

Common Mistakes

Assuming kVA and kW are the same value — they are only equal at unity power factor (PF = 1), which real inductive loads rarely have.

Frequently Asked Questions

Why is my generator's usable kW less than its kVA rating?

Because real (usable) power equals kVA multiplied by the load's power factor, which is normally below 1 for motor and inductive loads.

What power factor should I assume for a mixed industrial load?

0.8–0.9 is typical for a factory with motors, lighting and general equipment, but check your electricity bill or panel meter for the actual value.

These calculators are provided for informational and estimation purposes. Results depend on the assumptions and input values used. Always verify critical engineering calculations against applicable standards, manufacturer specifications, site measurements, and qualified professional advice.