Watts to Amps Calculator
Convert watts to amps, or amps to watts, for home single-phase supplies, three-phase supplies and DC, allowing for power factor.
Home supply is 230 V in the UK, Pakistan, India and the UAE, and 120 V in the US. Saudi Arabia is moving from 127/220 V to 230/400 V. For three phase, use the voltage between two lines, often 400 V.
1 for heaters, kettles and irons. Motors, pumps and ACs are lower, often 0.8 to 0.9: check the label.
Current
8.7 amps
- In kilowatts
- 2 kW
- Apparent power
- 2 kVA
2,000 W at 230 V draws 8.7 A.
How it's worked out
- Watts
V × A × PFpower factor allows for current that does no work - Current
2,000 ÷ (230 × 1)8.696 A
- For three phase, the current is per line. Choose cables and breakers with a qualified electrician; they allow for starting currents and cable length.
The formulas
DC: watts = volts × amps. AC single phase: watts = volts × amps × power factor. AC three phase: watts = √3 × line voltage × amps × power factor. The calculator rearranges these to find amps.
Questions people ask
How many amps is 2,000 W at 230 V?
About 8.7 A for a heater or kettle (power factor 1): 2,000 ÷ 230.
How many amps is 10 kW on a 400 V three-phase supply?
About 16 A per line at a power factor of 0.9: 10,000 ÷ (1.732 × 400 × 0.9).
What is power factor?
The share of the current that does useful work. It's 1 for heaters and kettles; motors, pumps and ACs are lower, so they draw more amps for the same watts.
Can I use this to choose a breaker or cable?
As a first guide only. An electrician allows for starting currents, cable length and the local wiring rules.
About this calculator
Formula and rules last checked 10 November 2026Written and tested by the CalculatorDex teamReport a problem
Sources: US Department of Energy: Determining electric motor load and efficiency (three-phase power, PDF) · UK Electricity Safety, Quality and Continuity Regulations 2002, regulation 27 (230 V) · US Department of Energy: Electricity 101 (120 V) · SASO: Saudi Arabia's move to 230/400 V