How to convert volts to watts
How to convert electrical voltage in volts (V) to electric power in watts (W).
You can calculate watts from volts and amps, but you can't convert volts to watts since watts and volts units do not measure the same quantity.
DC volts to watts calculation formula
The power P in watts is equal to the voltage V in volts, times the current I in amps:
P(W) = V(V) × I(A)
So watts are equal to volts times amps:
watt = volt × amp
or
W = V × A
Example
What is power consumption in watts when the current is 3A and the voltage supply is 15V?
Answer: the power P is equal to current of 3 amps times the voltage of 15 volts.
P = 15V × 3A = 45W
AC single phase volts to watts calculation formula
The real power P in watts is equal to the power factor PF times the phase current I in amps, times the RMS voltage V in volts:
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 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 volts to watts calculation formula
The real power P in watts is equal to square root of 3 times the power factor PF times the phase current I in amps, times the line to line RMS voltage VL-L in volts:
P(W) = √3 × PF × I(A) × VL-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(W) = √3 × 0.8 × 3A × 110V = 457W
How to convert watts to volts ►