# Watts to Amps Calculator

Electric power in watts (W) to electric current in amps (A) calculator.

* Use e for scientific notation. E.g: 5e3, 4e-8, 1.45e12

## DC watts to amps calculation

The current *I* in amps (A) is equal to the power *P* in watts (W), divided by
the voltage *V* in volts (V):

*I*

_{(A)}=

*P*

_{(W)}

*V*

_{(V)}

#### Example

*P* = 200W, *V* = 40V

*I*=

## AC single phase watts to amps calculation

The phase current *I* in amps (A) is equal to the power *P* in
watts (W), divided by the power factor *PF* times the RMS voltage *V* in volts (V):

*I*

_{(A)}=

*P*

_{(W)}

*PF*×

*V*

_{(V)}

The power factor of resistive impedance load is equal to 1.

#### Example

*P* = 2000W, *V* = 110V, *PF* = 0.8

*I*=

## AC three phase watts to amps calculation

#### Calculation with line to line voltage

The phase current *I* in amps (A) is equal to the power *P* in
watts (W), divided by square root of 3 times the power factor *PF* times the line to line RMS voltage *V*_{L-L} in volts (V):

*I*

_{(A)}=

*P*

_{(W)}

*√*3 ×

*PF*×

*V*

_{L-L(V)}

The power factor of resistive impedance load is equal to 1.

#### Calculation with line to neutral voltage

The phase current *I* in amps (A) is equal to the power *P* in
watts (W), divided by 3 times the
power factor *PF* times the line to neutral RMS voltage *V*_{L-N} in volts (V):

*I*

_{(A)}=

*P*

_{(W)}3 ×

*PF*×

*V*

_{L-N(V)}

The power factor of resistive impedance load is equal to 1.

## Typical power factor values

Do not use typical power factor values for accurate calculations.

Device | Typical power factor |
---|---|

Resistive load | 1 |

Fluorescent lamp | 0.95 |

Incandescent lamp | 1 |

Induction motor full load | 0.85 |

Induction motor no load | 0.35 |

Resistive oven | 1 |

Synchronous motor | 0.9 |

## Watts to amps table (120V)

Power (W) | Voltage (V) | Current (A) |
---|---|---|

10 watts | 120 volts | 0.0833 amps |

20 watts | 120 volts | 0.167 amps |

30 watts | 120 volts | 0.250 amps |

40 watts | 120 volts | 0.333 amps |

50 watts | 120 volts | 0.417 amps |

60 watts | 120 volts | 0.500 amps |

70 watts | 120 volts | 0.583 amps |

80 watts | 120 volts | 0.667 amps |

90 watts | 120 volts | 0.750 amps |

100 watts | 120 volts | 0.833 amps |

200 watts | 120 volts | 1.667 amps |

300 watts | 120 volts | 2.500 amps |

400 watts | 120 volts | 3.333 amps |

500 watts | 120 volts | 4.167 amps |

600 watts | 120 volts | 5.000 amps |

700 watts | 120 volts | 5.833 amps |

800 watts | 120 volts | 6.666 amps |

900 watts | 120 volts | 7.500 amps |

1000 watts | 120 volts | 8.333 amps |