# Watts to amps calculator

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

Select current type, enter
power in watts,
voltage in volts,
power factor for AC circuit and press the *
Calculate* button (DC = Direct Current, AC = Alternating Current):

## 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)}

## 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.

## 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 |

Fluorecent 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 |