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 VL-L in volts (V):
I(A) = P(W) / (√3 × PF × VL-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 VL-N in volts (V):
I(A) = P(W) / (3 × PF × VL-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 |
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