Amps to kW UK
Convert amps to kW on the UK 230 V single-phase or 400 V three-phase supply and compare it with standard UK circuit ratings.
Inputs
UK circuit ratings at this supply
How amps to kW UK calculator works
The amps to kW UK calculator converts current into kilowatts (kW) on the UK 230 V single-phase or 400 V three-phase supply with 3 inputs: current, power factor and phase. The column chart compares the load with 7 standard UK circuit ratings.
P = I × 230 × PF / 100013 A at 230 V gives 2.99 kW, the limit of a standard UK plug with a 13 A fuse (BS 1363).
Amps to kW UK formula
The amps to kW UK formula is P(kW) = I(A) × 230 × PF / 1,000 for single phase. There are 2 UK supply formulas: 230 V single phase and 400 V three phase.
230 V single phase
P = I × 230 × PF / 100013 A × 230 V / 1,000 = 2.99 kW
400 V three phase
P = √3 × I × 400 × PF / 10001.732 × 32 A × 400 V / 1,000 = 22.17 kW
Amps from kW
I = P × 1000 / (230 × PF)7 kW × 1,000 / 230 V = 30.43 A
UK mains is 230 V single phase and 400 V three phase at 50 hertz (Hz), with a tolerance of +10% and −6% under the Electricity Safety, Quality and Continuity Regulations 2002. Circuits follow BS 7671, the IET Wiring Regulations.
Amps to kW UK conversion chart
The amps to kW UK conversion chart lists 13 UK fuse, breaker and supply ratings from 3 A to 100 A at 230 V single phase and 400 V three phase, plus 230 V at power factor 0.9.
| Amps | 230 VPF 1 | 230 VPF 0.9 | 400 V 3φPF 1 |
|---|---|---|---|
| 3 A | 0.69 | 0.62 | 2.08 |
| 5 A | 1.15 | 1.04 | 3.46 |
| 6 A | 1.38 | 1.24 | 4.16 |
| 10 A | 2.3 | 2.07 | 6.93 |
| 13 A | 2.99 | 2.69 | 9.01 |
| 16 A | 3.68 | 3.31 | 11.09 |
| 20 A | 4.6 | 4.14 | 13.86 |
| 32 A | 7.36 | 6.62 | 22.17 |
| 40 A | 9.2 | 8.28 | 27.71 |
| 45 A | 10.35 | 9.32 | 31.18 |
| 63 A | 14.49 | 13.04 | 43.65 |
| 80 A | 18.4 | 16.56 | 55.43 |
| 100 A | 23 | 20.7 | 69.28 |
A 3 A plug fuse covers loads up to 0.69 kW, and a 13 A fuse covers loads up to 2.99 kW.
Amps to kW UK Excel formula
The amps to kW UK Excel formula is =A2*230*B2/1000 with amps in A2 and power factor in B2. Use =SQRT(3)*A2*400*B2/1000 for 400 V three phase.
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Amps | Volts | PF | kW | Formula in D |
| 2 | 13 | 230 | 1 | 2.99 | =ROUND(A2*B2*C2/1000,2) |
| 3 | 32 | 230 | 1 | 7.36 | =ROUND(A3*B3*C3/1000,2) |
| 4 | 32 | 400 | 1 | 22.17 | =ROUND(SQRT(3)*A4*B4*C4/1000,2) |
Row 3 is a 7.4 kW home electric vehicle (EV) charger on a 32 A circuit.
Amps to kW UK equation
The amps to kW UK equation is P = I × 230 × PF / 1,000 for a UK single-phase circuit.
- P
- Real power in kW
- I
- Current in amperes (A)
- 230
- UK nominal voltage (V)
- PF
- Power factor
Each amp on a UK 230 V circuit adds 0.23 kW at PF 1.
Amps to kW UK FAQ
How many kW is a 13 amp plug?
A 13 amp plug supplies up to 2.99 kW at 230 V, usually rounded to 3 kW.
How many kW is a 100 amp UK supply?
A 100 amp UK supply is 23 kW single phase at 230 V and 69.28 kW three phase at 400 V, at a power factor of 1.
What is the UK mains voltage?
UK mains voltage is 230 V single phase and 400 V three phase at 50 Hz, with an allowed range of 216 V to 253 V.
How many amps is 7 kW in the UK?
7 kW in the UK is 30.43 A at 230 V, which needs a 32 A circuit.