Electrical power tells you how much energy an appliance or circuit consumes (or delivers) each second, measured in watts.
Electrical power tells you how much energy an appliance or circuit consumes (or delivers) each second, measured in watts. It's found by multiplying the voltage across a component by the current flowing through it.
A device runs on 120 V and draws 2.5 A. Power = 120 × 2.5 = 300 W.
Power (watts) = voltage (volts) × current (amps), the basic form of the power formula (P = VI).
Combined with Ohm's Law (V = IR), power can also be expressed as P = I²R or P = V²/R depending on which values you know.
Watts tell you total power draw, while amps tell you the current draw at a given voltage — useful for checking against circuit breaker limits.