In electricity, kW stands for kilowatt, which is a unit of power. It measures the rate at which an electrical device or load uses energy. One kilowatt is equal to 1,000 watts. On the other hand, kWh stands for kilowatt-hour, which is a unit of energy. It measures the amount of energy that an appliance or device needs to run for one hour. One kilowatt-hour is equal to one kilowatt of power sustained for one hour. It is commonly used in billing for delivered energy to consumers by electric utility companies. To calculate kWh, you can multiply the power consumption of an appliance in kilowatts by the number of hours it is used.