# How to convert amps to watts

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

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

### DC amps to watts calculation formula

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

*P*_{(W)} = *I*_{(A)}* *×* V*_{(V)}

So watts are equal to amps times volts:

watt = amp × volt

or

W = A × V

#### Example

What is power consumption in watts when the current is 3A and the voltage supply is 110V?

Answer: the power P is equal to current of 3 amps times the voltage of 110 volts.

*P* = 3A × 110V = 330W

### AC single phase amps to watts calculation formula

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

*P*_{(W)} = * PF *×* I*_{(A)}* *×* V*_{(V)}

So watts are equal to power factor times amps times volts:

watt = * PF *×* *amp × volt

or

W = * PF *×* *A × V

#### Example

What is power consumption in watts when the power factor is 0.8 and the phase current is 3A and the RMS voltage supply is 110V?

Answer: the power P is equal to power factor of 0.8 times current of 3 amps times voltage of 110 volts.

*P* = 0.8 × 3A × 110V = 264W

### AC three phase amps to watts calculation formula

#### Watts calculation with line to line voltage

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

*P*_{(W)} = *√*3
× * PF *×* I*_{(A)}* *×* V*_{L-L(V)}

So watts are equal to square root of 3 times power factor PF times amps times volts:

watt = *√*3
× * PF *×* *amp × volt

or

W = *√*3
× * PF *×* *A × V

##### Example

What is power consumption in watts when the power factor is 0.8 and the phase current is 3A and the RMS voltage supply is 110V?

Answer: the power P is equal to power factor of 0.8 times current of 3 amps times the voltage of 110 volts.

*P* = *√*3
× 0.8 × 3A × 110V = 457W

#### Watts calculation with line to neutral voltage

The calculation assumes the loads are balanced.

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

*P*_{(W)} = 3 × * PF *×* I*_{(A)}* *×* V*_{L-0(V)}

So watts are equal to 3 times power factor PF times amps times volts:

watt = 3 × * PF *×* *amp × volt

or

W = 3 × * PF *×* *A × V

How to convert watts to amps ►

## See also

- Amps to watts calculator
- How to convert watts to amps
- How to convert kilowatts to amps
- How to convert amps to kilowatts
- 1 amps to watts calculation
- 2 amps to watt calculation
- 3 amps to watt calculation
- 10 amps to watt calculation
- 15 amps to watt calculation
- 100 amps to watt calculation
- Power factor
- Amp
- Volt
- Watt
- Electrical calculation
- Power conversion