SettingsSettings for this calculationUS
The line-to-line voltage of the three-phase system.
Common commercial/industrial three-phase voltages include 208V, 240V, and 480V.
The current draw per phase, in amps.
Check the equipment's nameplate rating or a clamp meter reading.
The load's power factor — 1.0 is purely resistive, motors are typically lower.
0.8-0.9 is a common range for industrial motor loads when the exact value isn't specified.
Real power
35.33 kW
- Apparent power
- 41.57 kVA
They open the calculator with your figures already in it
Three-Phase Power Calculator: 35.33 kW — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Standard three-phase power formula: P = sqrt(3) x V x I x power factor
Inputs used
- Line Voltage (V)
- 480
- Current (A)
- 50
- Power Factor
- 0.85
Intermediate steps
- Apparent power
- 41.57 kVA
What this calculation does not cover
- BALANCED loads only. The square root of three assumes the three phases carry equal current; an unbalanced load puts current in the neutral and the phase currents stop being interchangeable, so a single measured current no longer describes the system.
- The power factor entered has to be the TRUE power factor, not the displacement factor alone. Variable-speed drives, LED drivers and switched-mode supplies draw harmonic current that adds to the apparent power without adding real power, and a meter reporting only displacement will flatter the answer.
- Sizing conductors and protection from this figure means going through current, not kilowatts: ampacity, voltage drop, the protective device and any derating for grouping or ambient temperature are separate calculations, and the kW here is an input to none of them directly.
- Motor loads draw far more than their running current at start-up — several times, depending on the starting method — and it is the starting condition that sizes the protection and stresses the supply.
- Harmonic current also loads the neutral in a way the phase figures do not show. On a three-phase supply with many single-phase electronic loads, the triplen harmonics add rather than cancel in the neutral, which is why a neutral sized to match the phases can still run hot.
Add the equipment this sizes
This result is a specification — 35.33 kW — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-02 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Standard three-phase power formula: P = sqrt(3) x V x I x power factor
Cite this page
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