By Carla Boulianne
Updated Mar 24, 2022
The unit of measurement for electrical power is the watt. One watt equals one joule per second, representing the work done or electricity consumed each second. Power is calculated by multiplying voltage by current.
Voltage is the electric potential difference that drives current through a circuit, analogous to water pressure in a hose. One volt equals one joule per coulomb.
Current is the flow of electric charge over time, measured in amperes (amps). One ampere equals one coulomb per second, comparable to water flow rate.
W (watts) = V (volts) × I (amperes). In practice, a 60‑watt bulb consumes 60 joules per second, and its wattage equals the product of the operating voltage and the current drawn.
Understanding wattage helps consumers choose efficient appliances and manage energy consumption effectively.
