What is the difference between kVA and kW?

kVA (kilovolt-amperes) is apparent power — the total power drawn from the supply. kW (kilowatts) is real or active power — the portion that does actual work. The ratio between them is the power factor. kW = kVA × power factor.

What is a typical power factor?

Most resistive loads (heaters, incandescent lamps) have a power factor close to 1.0. Motors and inductive loads typically range from 0.7 to 0.9. Many data-center UPS units operate at 0.8 to 0.9. Capacitive correction can push the factor toward 1.0.

Why does power factor matter for energy calculations?

A lower power factor means more apparent power (kVA) is needed to deliver the same real energy (kWh). Utilities often charge large consumers for poor power factor because it increases current in transmission lines without delivering usable energy.

Can I use this for single-phase and three-phase systems?

Yes. The formula kWh = kVA × PF × hours applies to both single-phase and three-phase systems as long as the kVA value is the total apparent power of the system (i.e., already accounts for three phases).

What if I only know the kW rating, not kVA?

If you know the real power in kW, you do not need a power factor conversion — kWh = kW × hours directly. This tool is specifically for converting from apparent power (kVA) when the power factor is known.

kVA to Kilowatt Hours Calculator

Enter apparent power in kVA, a power factor, and duration in hours to instantly calculate energy consumption in kilowatt-hours.

Input Values

Apparent Power (kVA)

Kilovolt-amperes rated on the equipment nameplate.

Power Factor (0.01 – 1.00)

Typical range: 0.70 (motors) to 1.00 (resistive loads).

Duration (hours)

Number of hours the load operates.

Results

Fill in the inputs and click Calculate

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Summary

This calculator converts apparent power measured in kilovolt-amperes (kVA) to energy consumption in kilowatt-hours (kWh). The conversion requires a power factor value between 0 and 1, which represents how efficiently electrical power is used. The formula is: kWh = kVA × Power Factor × Hours.

How it works

Enter the apparent power value in kilovolt-amperes (kVA).
Enter the power factor (a dimensionless number from 0.01 to 1.00; typical devices range from 0.7 to 0.95).
Enter the time duration in hours over which the load operates.
The calculator multiplies kVA × power factor to get kilowatts (kW), then multiplies by hours to get kWh.
Click Calculate or press Enter to view the results.

Use cases

Estimate energy consumption of a generator or UPS system.
Calculate electricity costs for industrial equipment rated in kVA.
Size battery banks by knowing total kWh demand over a period.
Convert transformer ratings to expected energy throughput.
Verify utility billing estimates for commercial installations.
Compare energy usage of equipment with different power factors.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu