How to convert watts to amps

How to convert electric power in watts (W) to electric current in amps (A).

You can calculate amps from watts and volts. You can't convert watts to amps since watts and amps units do not measure the same quantity.

DC watts to amps calculation formula

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)

So amps are equal to watts divided by volts.

amp = watt / volt

or

A = W / V

Example

What is the current in amps when the power consumption is 330 watts and the voltage supply is 110 volts?

I = 330W / 110V = 3A

AC single phase watts to amps calculation formula

The phase current I in amps (A) is equal to the real 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) )

So amps are equal to watts divided by power factor times volts.

amps = watts / (PF × volts)

or

A = W / (PF × V)

Example

What is the phase current in amps when the power consumption is 330 watts, the power factor is 0.8 and the RMS voltage supply is 110 volts?

I = 330W / (0.8 × 110V) = 3.75A

AC three phase watts to amps calculation formula

Amps calculation with line to line voltage

The phase current I in amps (A) is equal to the real 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) )

So amps are equal to watts divided by square root of 3 times power factor times volts.

amps = watts / (3 × PF × volts)

or

A = W / (3 × PF × V)

Example

What is the phase current in amps when the power consumption is 330 watts, the power factor is 0.8 and the RMS voltage supply is 110 volts?

I = 330W / (3 × 0.8 × 110V) = 2.165A

Amps calculation with line to neutral voltage

The calculation assumes the loads are balanced.

The phase current I in amps (A) is equal to the real power P in watts (W), divided by 3 times the power factor PF times the line to neutral RMS voltage VL-0 in volts (V):

I(A) = P(W) / (3 × PF × VL-0(V) )

So amps are equal to watts divided by 3 times power factor times volts.

amps = watts / (3 × PF × volts)

or

A = W / (3 × PF × V)

 

How to convert amps to watts ►

 


See also

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