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kW to Current Calculator (kW to Amps)

Calculate Smarter. Work Faster.

Free kW to current calculator — enter kW, voltage, power factor and efficiency to get the current in amps for single-phase or three-phase loads and motors. Works in reverse too: current to kW.

Power & Current Details

Choose supply type and direction, then enter your values. Results update as you type.

Supply Type
Conversion Direction
Three-phase: enter line-to-line voltage.
1.0 for heaters
100 = general load · motor ≈ 85–95
For motors, enter the nameplate (shaft) kW and set efficiency.
1-ph: I = kW×1000 / (V×PF×η) 3-ph: I = kW×1000 / (√3×V×PF×η) kW = √3×V×I×PF / 1000
Load Current
— A

Converted using voltage, power factor & efficiency

Apparent Power—
Electrical Input—
Power in HP / CV (CP)—
Formula Used
Enter values and hit calculate to see the worked formula.
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Created by Umasankar Maity — B.Tech in Electrical Engineering, with 11+ years of industrial maintenance experience.

Reviewed by the ElectroMechCalc editorial team.

Last reviewed: September 2026  |  Standards referenced: IEC / IEEE / BIS / NEC

How it works

How to Calculate Current from kW

Quick answer: three-phase current I = kW × 1000 ÷ (1.732 × V × PF × η). Single-phase I = kW × 1000 ÷ (V × PF × η). Example: 10 kW at 415 V, PF 0.9 → about 15.5 A.

kW is the real power a load uses. To find the current, you need three more values: voltage, power factor (PF) and, for motors, efficiency (η).

Three-phase formulas add √3 (≈1.732). Always use line-to-line voltage for three-phase and line-to-neutral voltage for single-phase.

kW to Current Formula

Single-phase current
I =kW × 1000V × PF × η
Three-phase current
I =kW × 1000√3 × V × PF × η
Single-phase power
kW =V × I × PF1000
Three-phase power
kW =√3 × V × I × PF1000
DC current
I =kW × 1000V

I = current (A) · kW = real power · V = voltage · PF = power factor · η = efficiency as a decimal (1.0 for heaters and general loads; a motor's nameplate kW is shaft output, so divide by η).

Worked Examples

2.2 kW load at 240 V

Resistive load on a 2-pole breaker, 12 AWG conductors.

I = 2200 ÷ 240

I ≈ 9.17 A

12.5 kW, 230 V, PF 0.86

Line current of a single-phase AC circuit.

I = 12500 ÷ (230 × 0.86)

I ≈ 63.2 A

7.5 kW motor, 415 V 3-phase

PF 0.85, efficiency 89% (typical values).

I = 7500 ÷ (1.732 × 415 × 0.85 × 0.89)

I ≈ 13.8 A

16 A at 230 V to kW

Single-phase socket circuit, PF 1.

kW = 230 × 16 × 1 ÷ 1000

P = 3.68 kW

The 2.2 kW case is common in exam questions. A 2-pole breaker at 240 V is still a single-phase circuit. Breaker and conductor sizing are separate checks — the load current is only the starting point.

Motor Full-Load Current from kW (3-Phase)

Estimated full-load current for common motor sizes. PF and efficiency rise with motor size, so each row uses typical values for that size. For HP input, NEC table values and starting current, use the Motor Current Calculator.

Motor (kW)HPPFη400 V415 V460 V
0.75 kW1.00.7580%1.8 A1.7 A1.6 A
1.1 kW1.50.7883%2.5 A2.4 A2.1 A
1.5 kW2.00.8085%3.2 A3.1 A2.8 A
2.2 kW3.00.8186%4.6 A4.4 A4.0 A
3.7 kW5.00.8287%7.5 A7.2 A6.5 A
5.5 kW7.40.8488%10.7 A10.4 A9.3 A
7.5 kW10.10.8589%14.3 A13.8 A12.4 A
11 kW14.80.8590%20.8 A20.0 A18.0 A
15 kW20.10.8691%27.7 A26.7 A24.1 A
18.5 kW24.80.8691%34.1 A32.9 A29.7 A
22 kW29.50.8692%40.1 A38.7 A34.9 A
30 kW40.20.8692%54.7 A52.8 A47.6 A
37 kW49.60.8793%66.0 A63.6 A57.4 A
45 kW60.30.8793%80.3 A77.4 A69.8 A
55 kW73.80.8794%97.1 A93.6 A84.4 A
75 kW100.60.8894%130.9 A126.1 A113.8 A
90 kW120.70.8895%155.4 A149.8 A135.1 A

Illustrative estimates, not nameplate data. Actual FLA varies by manufacturer, pole count and efficiency class (IE2/IE3/IE4). Always use the nameplate FLA when available.

Popular kW to Amps Conversions

Quick answers for frequently searched loads (η = 1).

LoadVoltageSupplyPFCurrent
1 kW230 V1-phase1.04.35 A
2 kW220 V1-phase1.09.09 A
2.2 kW240 V1-phase1.09.17 A
3.68 kW230 V1-phase1.016.00 A
4 kW220 V1-phase1.018.18 A
5 kW230 V1-phase1.021.74 A
9.5 kW240 V1-phase1.039.58 A
12.5 kW230 V1-phase0.8663.20 A
15 kW400 V3-phase0.8525.5 A
40 kW400 V3-phase0.9064.2 A
60 kW415 V3-phase0.9092.7 A
230 kW415 V3-phase0.90355.5 A

Reverse direction — current to kW:

CurrentVoltageSupplyPFPower
13 A230 V1-phase1.02.99 kW
16 A230 V1-phase1.03.68 kW
32 A230 V1-phase1.07.36 kW
16 A400 V3-phase0.909.98 kW
63 A415 V3-phase0.9040.75 kW

Single-Phase vs Three-Phase Current

For the same kW, three-phase draws much less current per conductor. That keeps cable size, voltage drop and losses lower.

LoadSingle-phase (230V, PF 0.9)Three-phase (415V, PF 0.9)
5 kW24.2 A7.7 A
10 kW48.3 A15.5 A
20 kW96.6 A30.9 A
50 kW241.5 A77.3 A
100 kW483.1 A154.6 A

3-phase to single-phase current: for equal kW and PF, I(1-ph) = I(3-ph) × √3 × V(L-L) ÷ V(1-ph). On a 400 V / 230 V system that is about 3 × the three-phase current.

kW to Current Quick Reference Table (1-100 kW)

Every whole kW from 1 to 100 at PF 0.9 (η = 1). Scroll inside the table.

kWSingle-phase (230V, PF 0.9)Three-phase (415V, PF 0.9)
1 kW4.8 A1.5 A
2 kW9.7 A3.1 A
3 kW14.5 A4.6 A
4 kW19.3 A6.2 A
5 kW24.2 A7.7 A
6 kW29.0 A9.3 A
7 kW33.8 A10.8 A
8 kW38.6 A12.4 A
9 kW43.5 A13.9 A
10 kW48.3 A15.5 A
11 kW53.1 A17.0 A
12 kW58.0 A18.5 A
13 kW62.8 A20.1 A
14 kW67.6 A21.6 A
15 kW72.5 A23.2 A
16 kW77.3 A24.7 A
17 kW82.1 A26.3 A
18 kW87.0 A27.8 A
19 kW91.8 A29.4 A
20 kW96.6 A30.9 A
21 kW101.4 A32.5 A
22 kW106.3 A34.0 A
23 kW111.1 A35.6 A
24 kW115.9 A37.1 A
25 kW120.8 A38.6 A
26 kW125.6 A40.2 A
27 kW130.4 A41.7 A
28 kW135.3 A43.3 A
29 kW140.1 A44.8 A
30 kW144.9 A46.4 A
31 kW149.8 A47.9 A
32 kW154.6 A49.5 A
33 kW159.4 A51.0 A
34 kW164.3 A52.6 A
35 kW169.1 A54.1 A
36 kW173.9 A55.6 A
37 kW178.7 A57.2 A
38 kW183.6 A58.7 A
39 kW188.4 A60.3 A
40 kW193.2 A61.8 A
41 kW198.1 A63.4 A
42 kW202.9 A64.9 A
43 kW207.7 A66.5 A
44 kW212.6 A68.0 A
45 kW217.4 A69.6 A
46 kW222.2 A71.1 A
47 kW227.1 A72.7 A
48 kW231.9 A74.2 A
49 kW236.7 A75.7 A
50 kW241.5 A77.3 A
51 kW246.4 A78.8 A
52 kW251.2 A80.4 A
53 kW256.0 A81.9 A
54 kW260.9 A83.5 A
55 kW265.7 A85.0 A
56 kW270.5 A86.6 A
57 kW275.4 A88.1 A
58 kW280.2 A89.7 A
59 kW285.0 A91.2 A
60 kW289.9 A92.7 A
61 kW294.7 A94.3 A
62 kW299.5 A95.8 A
63 kW304.3 A97.4 A
64 kW309.2 A98.9 A
65 kW314.0 A100.5 A
66 kW318.8 A102.0 A
67 kW323.7 A103.6 A
68 kW328.5 A105.1 A
69 kW333.3 A106.7 A
70 kW338.2 A108.2 A
71 kW343.0 A109.8 A
72 kW347.8 A111.3 A
73 kW352.7 A112.8 A
74 kW357.5 A114.4 A
75 kW362.3 A115.9 A
76 kW367.1 A117.5 A
77 kW372.0 A119.0 A
78 kW376.8 A120.6 A
79 kW381.6 A122.1 A
80 kW386.5 A123.7 A
81 kW391.3 A125.2 A
82 kW396.1 A126.8 A
83 kW401.0 A128.3 A
84 kW405.8 A129.8 A
85 kW410.6 A131.4 A
86 kW415.5 A132.9 A
87 kW420.3 A134.5 A
88 kW425.1 A136.0 A
89 kW430.0 A137.6 A
90 kW434.8 A139.1 A
91 kW439.6 A140.7 A
92 kW444.4 A142.2 A
93 kW449.3 A143.8 A
94 kW454.1 A145.3 A
95 kW458.9 A146.8 A
96 kW463.8 A148.4 A
97 kW468.6 A149.9 A
98 kW473.4 A151.5 A
99 kW478.3 A153.0 A
100 kW483.1 A154.6 A

Current to kW Quick Reference Table (1-100 A)

The reverse lookup: read a breaker or cable current rating straight across to kW (PF 0.9).

Current (A)Single-phase (230V, PF 0.9)Three-phase (415V, PF 0.9)
1 A0.21 kW0.65 kW
2 A0.41 kW1.29 kW
3 A0.62 kW1.94 kW
4 A0.83 kW2.59 kW
5 A1.03 kW3.23 kW
6 A1.24 kW3.88 kW
7 A1.45 kW4.53 kW
8 A1.66 kW5.18 kW
9 A1.86 kW5.82 kW
10 A2.07 kW6.47 kW
11 A2.28 kW7.12 kW
12 A2.48 kW7.76 kW
13 A2.69 kW8.41 kW
14 A2.90 kW9.06 kW
15 A3.10 kW9.70 kW
16 A3.31 kW10.35 kW
17 A3.52 kW11.00 kW
18 A3.73 kW11.64 kW
19 A3.93 kW12.29 kW
20 A4.14 kW12.94 kW
21 A4.35 kW13.59 kW
22 A4.55 kW14.23 kW
23 A4.76 kW14.88 kW
24 A4.97 kW15.53 kW
25 A5.17 kW16.17 kW
26 A5.38 kW16.82 kW
27 A5.59 kW17.47 kW
28 A5.80 kW18.11 kW
29 A6.00 kW18.76 kW
30 A6.21 kW19.41 kW
31 A6.42 kW20.05 kW
32 A6.62 kW20.70 kW
33 A6.83 kW21.35 kW
34 A7.04 kW22.00 kW
35 A7.25 kW22.64 kW
36 A7.45 kW23.29 kW
37 A7.66 kW23.94 kW
38 A7.87 kW24.58 kW
39 A8.07 kW25.23 kW
40 A8.28 kW25.88 kW
41 A8.49 kW26.52 kW
42 A8.69 kW27.17 kW
43 A8.90 kW27.82 kW
44 A9.11 kW28.46 kW
45 A9.31 kW29.11 kW
46 A9.52 kW29.76 kW
47 A9.73 kW30.41 kW
48 A9.94 kW31.05 kW
49 A10.14 kW31.70 kW
50 A10.35 kW32.35 kW
51 A10.56 kW32.99 kW
52 A10.76 kW33.64 kW
53 A10.97 kW34.29 kW
54 A11.18 kW34.93 kW
55 A11.38 kW35.58 kW
56 A11.59 kW36.23 kW
57 A11.80 kW36.87 kW
58 A12.01 kW37.52 kW
59 A12.21 kW38.17 kW
60 A12.42 kW38.82 kW
61 A12.63 kW39.46 kW
62 A12.83 kW40.11 kW
63 A13.04 kW40.76 kW
64 A13.25 kW41.40 kW
65 A13.46 kW42.05 kW
66 A13.66 kW42.70 kW
67 A13.87 kW43.34 kW
68 A14.08 kW43.99 kW
69 A14.28 kW44.64 kW
70 A14.49 kW45.28 kW
71 A14.70 kW45.93 kW
72 A14.90 kW46.58 kW
73 A15.11 kW47.23 kW
74 A15.32 kW47.87 kW
75 A15.53 kW48.52 kW
76 A15.73 kW49.17 kW
77 A15.94 kW49.81 kW
78 A16.15 kW50.46 kW
79 A16.35 kW51.11 kW
80 A16.56 kW51.75 kW
81 A16.77 kW52.40 kW
82 A16.97 kW53.05 kW
83 A17.18 kW53.69 kW
84 A17.39 kW54.34 kW
85 A17.59 kW54.99 kW
86 A17.80 kW55.64 kW
87 A18.01 kW56.28 kW
88 A18.22 kW56.93 kW
89 A18.42 kW57.58 kW
90 A18.63 kW58.22 kW
91 A18.84 kW58.87 kW
92 A19.04 kW59.52 kW
93 A19.25 kW60.16 kW
94 A19.46 kW60.81 kW
95 A19.66 kW61.46 kW
96 A19.87 kW62.10 kW
97 A20.08 kW62.75 kW
98 A20.29 kW63.40 kW
99 A20.49 kW64.05 kW
100 A20.70 kW64.69 kW

How Power Factor Changes the Current

Same 10 kW, same 415 V three-phase — only the PF changes.

Power FactorCurrent for 10 kW at 415 V (3-phase)
1.00 (unity)13.9 A
0.9514.6 A
0.8516.4 A
0.7019.9 A
0.50 (poor)27.8 A

Dropping from PF 0.95 to 0.5 nearly doubles the current. Cables, breakers and transformers must still carry it — which is why poor PF is penalised and APFC capacitor banks are used — size them with the APFC Capacitor Calculator.

kW to HP, CV, PS & CP (Cai Putere)

Mechanical horsepower (HP) and metric horsepower are not the same unit. CV (Spanish/Portuguese/Italian), PS (German), CP — cai putere (Romanian) — and LE (Hungarian) are all metric horsepower. For any value, use the HP to kW Calculator.

kW to mechanical HP
1 kW = 1.341 HP
kW to metric HP (CV · PS · CP · LE)
1 kW = 1.360 CP
kWHP (mechanical)CV / PS / CP / LE (metric)
1 kW1.3 HP1.4 CP
5.5 kW7.4 HP7.5 CP
7.5 kW10.1 HP10.2 CP
15 kW20.1 HP20.4 CP
25 kW33.5 HP34.0 CP
40 kW53.6 HP54.4 CP
55 kW73.8 HP74.8 CP
60 kW80.5 HP81.6 CP
75 kW100.6 HP102.0 CP
91 kW122.0 HP123.7 CP
100 kW134.1 HP136.0 CP
130 kW174.3 HP176.8 CP
150 kW201.2 HP203.9 CP
160 kW214.6 HP217.5 CP
200 kW268.2 HP271.9 CP

Reverse — metric horsepower (CP / CV) to kW (1 CP = 0.7355 kW):

CP / CV (metric)kW
100 CP73.6 kW
130 CP95.6 kW
140 CP103.0 kW
150 CP110.3 kW
160 CP117.7 kW

kW Load to Cable Size: The Workflow

kW load→Current (A)→Cable size→Voltage drop check

Find the current first, apply your code's continuous-load margin, then pick a cable and check voltage drop over the real run length.

Load (3-ph, 415 V, PF 0.9)CurrentDesign current (example ×1.25)Indicative Cu size
12 kW18.5 A23.2 A≈ 4 mm²
20 kW30.9 A38.6 A≈ 10 mm²
35 kW54.1 A67.6 A≈ 25 mm²
40 kW61.8 A77.3 A≈ 35 mm²
60 kW92.7 A115.9 A≈ 70 mm²
80 kW123.7 A154.6 A≈ 95 mm²
85 kW131.4 A164.2 A≈ 95 mm²

Indicative copper sizes for a short run in free air or tray, before derating for grouping, ambient temperature and installation method. The ×1.25 margin is an example only — use the factor your local code requires, then verify with the Cable Size Calculator and the Voltage Drop Calculator.

Typical current ratings used for the table above:

Cable Size (Copper)Typical Current RatingSuggested Use Case
2.5 mm²~20–24 ALighting, small sockets
4 mm²~28–32 ASmall motors, power sockets
10 mm²~45–55 ASmall three-phase motors
25 mm²~75–95 ASub-panel feeders
70 mm²~150–180 AMain distribution feeders

Common Mistakes

1. Assuming PF = 1. Only true for resistive loads like heaters. Motors need the real PF, or current is understated.

2. Using phase voltage on three-phase. Enter 400/415 V line-to-line, not 230/240 V — otherwise the result is off by √3.

3. Ignoring motor efficiency. Nameplate kW is shaft output. Electrical input = kW ÷ η, so skipping η understates current.

4. Sizing protection on running current only. Starting current is often 5–8× running current. Breakers must ride through it — estimate it with the Motor Starting Current Calculator.

5. Forgetting to recheck after PF correction. APFC changes supply current for the same kW — review cables and breakers after a retrofit.

Protection Sizing

From Current to Breaker & Overload Rating

General loads: the breaker is usually the next standard size at or above the load current, plus the continuous-load margin your local code requires.

Motor circuits: the breaker (or MPCB) is set high — often 150–250% of FLA — to ride through starting inrush. A thermal overload relay, set close to FLA (commonly 100–115%), protects the winding from running overload.

Exact settings depend on device type, trip curve, motor data and local code. Always confirm against the equipment datasheet.

Starting method and inrush current

DOL (Direct-On-Line): highest inrush, typically 6–8× FLA. Simplest and cheapest — suits small motors.

Star-Delta: cuts inrush to roughly 2–3× FLA, with lower starting torque. Common for medium motors (about 5.5 kW and above).

Soft starter / VFD: limits inrush to about 1.5–3× FLA with a smooth ramp. Used for larger motors, pumps, conveyors and compressors.

FAQ

Frequently Asked Questions

How do you calculate current from kW? +

Single-phase: I = (kW × 1000) ÷ (V × PF × η). Three-phase: I = (kW × 1000) ÷ (1.732 × V × PF × η), using line-to-line voltage. Use η = 1 for heaters and general loads, or the motor efficiency when kW is the motor's shaft output. Example: 10 kW, 415 V three-phase, PF 0.9 → about 15.5 A.

How much current does a 2.2 kW load draw at 240 V? +

For a resistive load (PF 1), I = 2200 ÷ 240 ≈ 9.17 A. A 2-pole breaker on a 240 V circuit does not make it three-phase — it is a single-phase circuit across two lines. Breaker rating and conductor size (for example 12 AWG copper, which the US NEC commonly limits to 20 A overcurrent protection) are separate checks against your local code.

How many amps does a 5.5 kW motor draw? +

Using typical values of PF 0.84 and 88% efficiency, a 5.5 kW three-phase motor draws about 10.4 A at 415 V and about 10.7 A at 400 V. This is an estimate — always use the nameplate full-load current (FLA) when it is available.

Why does three-phase power use √3 in the formula? +

In a balanced three-phase system the line-to-line voltage is √3 (≈1.732) times the phase voltage, because the phases are 120° apart. The √3 factor converts line voltage and line current into total three-phase power.

What voltage should I use — line voltage or phase voltage? +

Use line-to-line voltage for three-phase systems (e.g. 400 V or 415 V) and line-to-neutral voltage for single-phase (e.g. 230 V), which is how supply voltage is normally stated on nameplates in most countries. For a 240 V two-line circuit (North America), use 240 V with the single-phase formula.

Does a lower power factor mean higher current for the same kW load? +

Yes. kW is fixed by the load's useful power, so a lower PF means the same kW needs more current. Low-PF loads therefore need larger cables and breakers than a PF 1.0 load of the same kW.

How do I convert three-phase current to single-phase current for the same kW? +

For equal kW and PF, I(1-phase) = I(3-phase) × √3 × V(line-to-line) ÷ V(single-phase). On a 400 V / 230 V system this works out to roughly 3 times the three-phase line current.

Can I convert kWh to current? +

Not directly. kWh is energy, not power. Divide kWh by the running hours to get average kW, then use the kW to current formula. For example, 6 kWh used over 2 hours = 3 kW average.

Can I find kW from voltage alone, such as 415 V or 230 V? +

No. Voltage alone does not set power. You also need the current (and power factor for AC). For example, 16 A at 230 V with PF 1 = 3.68 kW, and 13 A at 230 V = about 2.99 kW.

How do I convert kW to HP, CV, PS or CP (cai putere)? +

1 kW = 1.341 mechanical HP. CV, PS, CP (cai putere) and LE are metric horsepower: 1 kW = 1.360 CV/PS/CP, and 1 CP = 0.7355 kW. So 55 kW ≈ 74.8 CP and 150 CP ≈ 110.3 kW.

What efficiency and power factor should I assume if the nameplate is missing? +

For standard induction motors, 85-95% efficiency and PF 0.8-0.88 are reasonable planning assumptions. Smaller motors sit at the lower end, larger motors at the higher end. Always prefer the actual nameplate values.

Is this calculator suitable for sizing cables or breakers directly? +

It gives the correct starting current or power. Final cable and breaker sizing must also account for ambient temperature, installation method, grouping, cable length (voltage drop) and your local wiring code — use the Cable Size Calculator as the next step.

Why do I need a separate overload relay if I already have a breaker? +

A motor breaker is set well above FLA (often 150-250%) to ride through starting inrush, so it will not react to a moderate running overload. A thermal overload relay set close to FLA protects the winding from that sustained overload.

Why does the same kW draw less current on 415 V than on 230 V? +

For a fixed power, current is inversely proportional to voltage. Higher voltage — and three-phase supply — delivers the same kW with less current, which means smaller cables and lower I²R losses.

Does this calculator work for DC loads? +

No — √3 and power factor are AC terms. For DC, I = (kW × 1000) ÷ V, with no power factor or phase multiplier.

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