How Many Amps Is 21.2 kW at 460V?

21.2 kW at 460V draws about 31.3 amps on an AC three-phase circuit at PF 0.85, typical for commercial HVAC, industrial motors, rooftop units, and three-phase panel loads. Actual current varies with equipment power factor and duty cycle.

21.2 kW at 460V, AC three-phase (PF 0.85)

31.3 Amps

21.2 kilowatts at 460V on AC three-phase ≈ 31.3 amps

AC Single Phase (PF 0.85)54.22 A

DC (ideal baseline)46.09 A

Try: 22kW at 460V 20kW at 460V 18kW at 460V 25kW at 460V

Volts

Amps (AC three-phase, PF 0.85)

31.3

Formulas

DC: kW to Amps

I_(A) = 1000 × P_(kW) ÷ V_(V)

1000 × 21.2 ÷ 460 = 21,200 ÷ 460 = 46.09 A

AC Single Phase (PF = 0.85)

I_(A) = 1000 × P_(kW) ÷ (PF × V_(V))

21,200 ÷ (0.85 × 460) = 21,200 ÷ 391 = 54.22 A

AC Three Phase (PF = 0.85)

I_(A) = 1000 × P_(kW) ÷ (√3 × PF × V_L-L), where V_L-L is the line-to-line voltage

21,200 ÷ (1.732 × 0.85 × 460) = 21,200 ÷ 677.21 = 31.3 A

Equipment & Circuit Sizing

Breaker Sizing

Breaker ratings are in amps, not watts, so the real install answer depends on the equipment nameplate FLA, whether the load is continuous (NEC 210.19(A) sizes the conductor and OCP at 125% of a continuous load, equivalently 80% of breaker rating), conductor ampacity and temperature rating, ambient and bundling derates, and any motor or HVAC provisions (NEC 430 / 440). At roughly 31.3A on AC three-phase at 460V, the load sits in the bracket between a 35A standard size (non-continuous) and the next size up that covers a continuous load under 210.19(A) (around 40A). The actual install pick depends on whether the load is continuous and the factors above; a conversion page can't pick a single "right" breaker from the amp draw alone.

Energy Cost

21.2 kW costs $3.60/hour at $0.17/kWh (rates last reviewed April 2026). See breakdown.

Power Factor Reference (AC three-phase)

How the line current for 21.2 kW at 460V changes with load power factor, on the same AC three-phase circuit basis the rest of the page uses. DC has no power factor; PF 1.0 represents resistive AC loads.

Load Type	PF	21.2 kW at 460V (AC three-phase)
Resistive (heaters, incandescent)	1	26.61 A
Fluorescent lamps	0.95	28.01 A
LED lighting	0.9	29.56 A
Synchronous motors	0.9	29.56 A
Typical mixed loads	0.85	31.3 A
Induction motors (full load)	0.8	33.26 A
Computers (without PFC)	0.65	40.94 A
Induction motors (no load)	0.35	76.02 A

AC Conversion Comparison

On DC, 21.2kW at 460V draws 46.09A. AC single-phase at PF 0.85 pulls 54.22A because reactive current is added on top of the real power. Three-phase at the same voltage needs only 31.3A per line since the same 21.2kW is shared across three conductors instead of one.

Circuit Type	Formula	Result
DC	21,200 ÷ 460	46.09 A
AC Single Phase (PF 0.85)	21,200 ÷ (0.85 × 460)	54.22 A
AC Three Phase (PF 0.85)	21,200 ÷ (1.732 × 0.85 × 460)	31.3 A

Other kW Values at 460V

kW	AC 3-Phase per line, PF 0.85	AC 1-Phase PF 0.85
3.5 kW	5.17 A	8.95 A
4 kW	5.91 A	10.23 A
5 kW	7.38 A	12.79 A
6 kW	8.86 A	15.35 A
7.5 kW	11.07 A	19.18 A
8 kW	11.81 A	20.46 A
10 kW	14.77 A	25.58 A
12 kW	17.72 A	30.69 A
15 kW	22.15 A	38.36 A
18 kW	26.58 A	46.04 A
20 kW	29.53 A	51.15 A
22 kW	32.49 A	56.27 A
25 kW	36.91 A	63.94 A
30 kW	44.3 A	76.73 A
35 kW	51.68 A	89.51 A

Same kW, Other Voltages

Each destination page leads with the interpretation most common for that voltage, so the amps shown below use the same basis as the page you'd land on: single-phase for residential voltages, three-phase for commercial/industrial panel voltages, DC for low-voltage.

electrical_services 21.2 kW at 24V = 883.33A (DC) electrical_services 21.2 kW at 208V = 69.23A (3-phase) electrical_services 21.2 kW at 220V = 113.37A (1-phase) electrical_services 21.2 kW at 230V = 108.44A (1-phase) electrical_services 21.2 kW at 240V = 103.92A (1-phase) electrical_services 21.2 kW at 400V = 36A (3-phase) electrical_services 21.2 kW at 480V = 30A (3-phase) electrical_services 21.2 kW at 575V = 25.04A (3-phase)

Related Calculations

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Frequently Asked Questions

How many amps is 21.2 kW at 460V?expand_more

21.2 kW at 460V draws about 31.3 amps on an AC three-phase circuit at PF 0.85. Alternate cases at the same voltage: 46.09A on DC, 54.22A on AC single-phase.

What is 21.2 kW in watts?expand_more

21.2 kW equals 21,200 watts. Multiply kilowatts by 1000.

What size breaker would I need for 21.2 kW at 460V?expand_more

This is a sizing question, not a conversion question, and there is no single correct answer from a page like this. Breaker selection depends on the equipment nameplate FLA, whether the load is continuous (NEC 210.19(A) applies the 125% continuous-load rule), the conductor ampacity and temperature rating, any NEC 430/440 motor or HVAC provisions, and local code interpretation. Use the nameplate and a licensed electrician for the real install value; use this page only for the current-draw estimate that feeds into that process.

How many amps does a 21.2 kW EV charger draw at 460V?expand_more

460V is commercial/industrial panel voltage, not a typical AC EVSE feed to a vehicle. On three-phase 460V, 21.2 kW works out to about 31.3A per line (three-phase at PF 0.85). In practice, 400-480V three-phase is usually the AC input to a DC fast charger (50-350 kW CCS/NACS stations like Tesla Superchargers), which rectifies to DC and delivers that directly to the vehicle, rather than an AC EVSE connector. A 21.2 kW figure at 460V is most likely the AC feed to a smaller commercial cabinet or the control-side input of a larger DC fast charger, not an at-the-car AC current.

Is 21.2 kW single-phase or three-phase?expand_more

21.2 kW is typically three-phase in commercial and industrial settings.

This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.