Watt Calculator: Watts, Volts, Amps and Ohms

Your details

DC uses P = V x I. AC single-phase adds a power factor: P = V x I x PF.
Choose which quantity to solve for. The other two inputs supply the known values.
Real power consumed or produced.
Select which two quantities you know. The calculator uses those to solve for the unknown.
PowerHigh power (1-10 kW)
1,200W

Real electrical power (watts)

Voltage120V
Current10A
Resistance12Ω
Power (kW)1.2kW
Apparent power1,200VA
Formula usedP = V × I
Power (W)1,200
Voltage (V)120
Current (A)10
Resistance (Ω)12

1.200 kW solved using P = V × I.

  • 1.20 kW is in the range of large appliances, HVAC units, or EV chargers.
  • The current draw is 10.0000 A.
  • Resistance is 12.0000 ohms; at this power level, verify the component's wattage rating to avoid overheating.

Next stepFor loads above 1 kW, calculate the daily energy cost: multiply kilowatts by hours of use and your electricity rate ($/kWh).

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