Difference Between kW and kWh


Main Difference

Understanding the differences between kilowatts (kW) and kilowatt-hours (kWh) is important to understand because of its impact on the consumption of your home energy and its bill. Although there are many differences between kW and kWh but the main difference between kW and kWh is that kW measures the power while kWh measures the energy.

What is kW?

kW stands for kilowatt and equal to one thousand watts. This unit is used to express the power generated by power engines and power of electric devices such as motors, machines, heaters and other tools. It is also used to express the electromagnetic power output of broadcast radio and TV transmitters. One kW is equal to 1.34 horsepower. A small electric heater containing one heating element consume approximately 1 kW.


What is kWh?

kWh is the symbol of kilowatt-hour. It is a unit of energy equivalent to one kilowatt of power consumed for one hour. One kWh is equal to 1,000 watt-hours or 3.6 megajoules. It can be understand as if the energy is being used at constant power over a period of time, the total energy in kWh is the product of the power in the kilowatts and the time in hours. It is the commonly used billing unit for energy transmitted to consumers by electric utilities.

Key Differences

  1. kW is a measure of power while kWh is a measure of energy.
  2. According to energy management theory, kW is referred to as ‘demand’ and kWh is referred to ‘usage’ or ‘consumption’.
  3. Less power electric home appliances uses some watts of power like bulb. Heavy motors, heaters, etc. uses kWh.
  4. kWh is greater unit than kW. One kWh is equal to 1,000 watt-hours.
  5. Electricity bills are calculated according to kWh.
  6. kWh calculate amount of energy for a specific period of time while kW calculate rates of power at a moment in time.
Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss