Converting amps to watts can be done using the power formula, which states that I = P ÷ E, where P is power measured in watts, I is current measured in amps, and E is voltage measured in volts.

DC amps to watts calculation

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)

AC single phase amps to watts calculation

The 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)

AC three phase amps to watts calculation

Calculation with line to line voltage

The 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)

Calculation with line to neutral voltage

The 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-N in volts (V):

P_(W) = 3 × PF × I_(A) × V_L-N(V)