Free tool
kW to kVA Calculator
Apparent power is real power divided by the power factor — and a motor's nameplate kW is shaft output, so efficiency has to come back in before the division.
kVA = kW ÷ power factor
kVA = kW ÷ PF. 80 kW at a power factor of 0.8 is 100 kVA. For a motor, divide the shaft kW by efficiency first: 7.5 kW at 90% and PF 0.85 is about 9.8 kVA at the terminals, not 8.8.
Current follows the kVA. Convert it with the kVA to amps calculator. The inverse conversion is kVA to kW.
The rating
Enter 500 W as 0.5.
Required. At PF 1, kVA equals kW.
The answer
Apparent power
100.00 kVA
kVA = kW ÷ PF → 80.00 ÷ 0.80
Also true at this PF
Real power at the electrical terminals: 80.00 kW. Reactive ≈ 60.00 kvar. Current follows the kVA — convert it with the kVA to amps calculator, not by dividing kW by volts.
What this does not tell you
Motor circuit sizing. NEC Article 430 sizes motor branch circuits from the FLC tables, not from this conversion. A generator pick for a building. That needs the load list and starting currents — conversion alone is not a size. Conductor or breaker size from the kVA without voltage, continuous-load and ambient inputs.
Informational use only, please verify before you rely on it
This reproduces the standard relationship between real power in kW and apparent power in kVA. It is a preparation aid, not a determination. Motor circuits are sized from NEC Article 430, not from this conversion. It does not size generators, transformers, conductors or overcurrent protection. Confirm against the equipment nameplate and with the authority having jurisdiction.
This tool is provided for general informational and educational purposes only. Its output is an illustrative estimate generated from the values you enter and from general assumptions that will not match every deal, market, lender, or homeowner. It is not tax, legal, accounting, financial, or professional advice, and it is not a quote, an offer, a credit decision, or a guarantee of pricing, approval, timing, savings, or eligibility.
You are solely responsible for independently confirming all information presented here including any figures, rates, fees, margins, timelines, tax treatment, and federal, state, local, or utility incentives, with the applicable lender, authority having jurisdiction, and your own qualified tax, legal, and financial advisors before acting on it, relying on it, or presenting it to a homeowner or any third party. Incentive programs, lender terms, and permitting requirements change frequently and vary by jurisdiction.
Seamless Home is not a tax advisor, law firm, lender, or licensed installing contractor, and makes no representation or warranty as to the accuracy, completeness, or currency of the information produced by this tool. To the fullest extent permitted by law, Seamless Home accepts no liability for any decision made or action taken in reliance on it.
The motor trap on this direction
Dividing a motor's nameplate kW by the power factor alone understates the supply because the plate is shaft output. The same trap appears in the other direction on the kW to amps calculator, which is why that tool asks what the rating describes before converting it. What power factor is explains the gap between kW and kVA on inductive loads.
Once you have the kVA, the current is a voltage question — kVA to amps — and the real-power inverse of this page is kVA to kW.
Frequently Asked Questions
How do you convert kW to kVA?+
Divide kW by the power factor: kVA = kW ÷ PF. 80 kW at a power factor of 0.8 is 100 kVA. At unity power factor the two figures are equal. For a motor whose nameplate states shaft output, divide by efficiency first to get electrical input, then by the power factor.
Why is a motor's kVA larger than kW ÷ PF?+
Because the nameplate kW is mechanical output at the shaft, not what the motor draws from the supply. Electrical input is shaft output divided by efficiency. A 7.5 kW (10 hp) motor at 90 percent efficiency and a power factor of 0.85 takes about 8.33 kW electrically and about 9.8 kVA — not the 8.8 kVA you would get by dividing 7.5 by 0.85 alone.
What is the difference between kW and kVA?+
kW is real power; kVA is apparent power. Wiring, transformers and generator nameplates are limited by kVA (and by current), while the work a load does is measured in kW. The ratio is the power factor.
Does this size a generator?+
No. Converting a kW figure to kVA tells you the apparent power of that figure at a stated power factor. It does not add starting currents, diversity or the rest of a building's load. Generator sizing is a separate calculation.
How do I get amps from the kVA?+
Use the kVA and the system voltage — amps = kVA × 1,000 ÷ volts on single-phase, and ÷ (volts × √3) on three-phase line-to-line. The kVA to amps calculator does that and flags line-to-neutral voltage mistakes.
What power factor should I use?+
The nameplate figure when it exists. Otherwise the known power factor of the load: near 1.0 for resistive heating, often 0.8–0.9 for motors under load. A guessed 0.8 is a planning assumption, not a measurement.
Is this a determination?+
No. It reproduces the standard relationship kVA = kW ÷ PF as a preparation aid. Motor branch circuits are sized from NEC Article 430 tables, not from this conversion. Confirm against the equipment nameplate and with the authority having jurisdiction.
Related resources
kVA to kW Calculator
The inverse — with a nameplate that lists both figures checked for consistency.
Learn more →kVA to Amps Calculator
Full-load current from the kVA you just calculated.
Learn more →kW to Amps Calculator
Current from a kW rating, including motor shaft output.
Learn more →What Is Power Factor?
Why motors and electronics separate kW from kVA.
Learn more →Load figures that match the equipment
Seamless Home runs the design, permit and interconnection layer for the partners it works with — which is where a motor or transformer rating gets read the way the nameplate wrote it. Coverage is confirmed per service area rather than promised as blanket availability.
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