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kVA to kW Calculator

Convert apparent power in kVA into real power in kW using a power factor.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-26 · v1.0.0

Market
Imperial · sales tax

Real power at PF 0.8

80 kW

High confidence

kW = kVA × power factor, taken here as 0.8. Assumes PF 0.8. Substitute the installation's actual power factor where it is known — the result scales directly with it.

Conversion factor applied
0.8 kW per kVA

Generators, transformers and supply capacities are rated in kVA while the work they do is measured in kW, and the gap between the two is the power factor. This calculator applies a conventional 0.8, which suits mixed commercial loading; a motor-heavy site sits lower and a corrected or largely resistive one higher, and the result scales directly so substituting a known figure is straightforward. The point most often missed is that generator sets carry both ratings for a reason. The kVA figure describes the alternator and the kW figure the engine, so a load with a poor power factor can saturate the alternator while the engine still has headroom, which is why sizing on kW alone leads to trouble.

Add the equipment this sizes

This result is a specification — 80 kW — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Real power = apparent power x power factor; kW = kVA x PF
  • Power factor 0.8 is a common assumption for mixed commercial loading; actual values vary by installation

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Frequently asked questions

Why is a power factor assumed?
Because kVA and kW differ only by it, and the true value depends on the installation's mix of motors, electronics and resistive load. 0.8 is a conventional planning assumption; a site with a large motor load may sit lower, and one dominated by corrected or resistive load higher.
Which figure do generators use?
Both, and it matters. Generator sets are rated in kVA for their alternator capacity and kW for their engine capacity. Sizing on the kW figure alone can leave the alternator overloaded by a poor power factor even though the engine has capacity to spare.
Can power factor be improved?
Yes, with correction equipment, and it is often worth doing where supply charges are based on kVA. Correction reduces the apparent power drawn for the same useful work, freeing capacity and sometimes reducing the tariff.