How Many Amps Is 25.4 kW at 400V?

25.4 kilowatts at 400V works out to roughly 43.12 amps on AC three-phase at PF 0.85. That is typical for commercial HVAC, industrial motors, rooftop units, and three-phase panel loads. See the DC and alternate-phase numbers below for other circuit types.

25.4 kW at 400V, AC three-phase (PF 0.85)

43.12 Amps

25.4 kilowatts at 400V on AC three-phase ≈ 43.12 amps

AC Single Phase (PF 0.85)74.69 A

DC (ideal baseline)63.49 A

Try: 25kW at 400V 22kW at 400V 30kW at 400V 20kW at 400V

Volts

Amps (AC three-phase, PF 0.85)

43.12

Formulas

DC: kW to Amps

I_(A) = 1000 × P_(kW) ÷ V_(V)

1000 × 25.4 ÷ 400 = 25,396 ÷ 400 = 63.49 A

AC Single Phase (PF = 0.85)

I_(A) = 1000 × P_(kW) ÷ (PF × V_(V))

25,396 ÷ (0.85 × 400) = 25,396 ÷ 340 = 74.69 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

25,396 ÷ (1.732 × 0.85 × 400) = 25,396 ÷ 588.88 = 43.12 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 43.12A on AC three-phase at 400V, the load sits in the bracket between a 45A standard size (non-continuous) and the next size up that covers a continuous load under 210.19(A) (around 60A). 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

25.4 kW costs $4.32/hour at $0.17/kWh (rates last reviewed April 2026). See breakdown.

Power Factor Reference (AC three-phase)

How the line current for 25.4 kW at 400V 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	25.4 kW at 400V (AC three-phase)
Resistive (heaters, incandescent)	1	36.66 A
Fluorescent lamps	0.95	38.59 A
LED lighting	0.9	40.73 A
Synchronous motors	0.9	40.73 A
Typical mixed loads	0.85	43.12 A
Induction motors (full load)	0.8	45.82 A
Computers (without PFC)	0.65	56.39 A
Induction motors (no load)	0.35	104.73 A

AC Conversion Comparison

On DC, 25.4kW at 400V draws 63.49A. AC single-phase at PF 0.85 pulls 74.69A because reactive current is added on top of the real power. Three-phase at the same voltage needs only 43.12A per line since the same 25.4kW is shared across three conductors instead of one.

Circuit Type	Formula	Result
DC	25,396 ÷ 400	63.49 A
AC Single Phase (PF 0.85)	25,396 ÷ (0.85 × 400)	74.69 A
AC Three Phase (PF 0.85)	25,396 ÷ (1.732 × 0.85 × 400)	43.12 A

Other kW Values at 400V

kW	AC 3-Phase per line, PF 0.85	AC 1-Phase PF 0.85
4 kW	6.79 A	11.76 A
5 kW	8.49 A	14.71 A
6 kW	10.19 A	17.65 A
7.5 kW	12.74 A	22.06 A
8 kW	13.58 A	23.53 A
10 kW	16.98 A	29.41 A
12 kW	20.38 A	35.29 A
15 kW	25.47 A	44.12 A
18 kW	30.57 A	52.94 A
20 kW	33.96 A	58.82 A
22 kW	37.36 A	64.71 A
25 kW	42.45 A	73.53 A
30 kW	50.94 A	88.24 A
35 kW	59.43 A	102.94 A
40 kW	67.92 A	117.65 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 25.4 kW at 208V = 82.93A (3-phase) electrical_services 25.4 kW at 220V = 135.81A (1-phase) electrical_services 25.4 kW at 230V = 129.9A (1-phase) electrical_services 25.4 kW at 240V = 124.49A (1-phase) electrical_services 25.4 kW at 460V = 37.5A (3-phase) electrical_services 25.4 kW at 480V = 35.94A (3-phase) electrical_services 25.4 kW at 575V = 30A (3-phase)

Related Calculations

bolt 25,396W to amps at 400V payments 25,396W running cost cable Wire size for 43.12A at 400V (3Φ)

Frequently Asked Questions

How many amps is 25.4 kW at 400V?expand_more

25.4 kW at 400V draws about 43.12 amps on an AC three-phase circuit at PF 0.85. Alternate cases at the same voltage: 63.49A on DC, 74.69A on AC single-phase.

How many amps does a 25.4 kW EV charger draw at 400V?expand_more

400V is commercial/industrial panel voltage, not a typical AC EVSE feed to a vehicle. On three-phase 400V, 25.4 kW works out to about 43.12A 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 25.4 kW figure at 400V 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 25.4 kW single-phase or three-phase?expand_more

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

What size breaker would I need for 25.4 kW at 400V?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.

What is the formula for kW to amps?expand_more

DC: Amps = (kW × 1000) ÷ Volts. AC single-phase: Amps = (kW × 1000) ÷ (Volts × PF). AC three-phase: Amps = (kW × 1000) ÷ (Volts_L-L × √3 × PF).

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.