Energy Unit Conversion Calculator

Creation and storage of energy provides the capacity to accomplish real work, although the delivery and load devices dictate the rate of consumption. This calculator will convert easily between common energy units.

Enter an original energy value and original unit system:

Select up to two output units and click 'Calculate' to view equivalent energy values:


Simply put, energy is the ability to do work. Batteries contain energy, so does fuel, water and air pressure, sunlight, and nearly everything else that moves. Harnessing the energy into circuits and systems is more difficult. The best energy sources have three important factors:

  1. They should have a high energy capacity per volume stored.
  2. They should be able to be stored in relatively small, safe containers.
  3. The process of storage should be relatively inexpensive.

Energy Units in Joules (J)

Most physics texts will use Joules (J) as the base unit for energy, both in electrical systems as well as the mechanical work equation of force x distance. For real motion systems, however, several other units are more common.

Energy Units in Kilowatt-Hours (kW-hr)

The kW-hr is the most common for energy production and consumption. Although kW alone is simply a rate of energy use at any moment, the total summation of energy over a period of time is kW-hrs. For some power customers, the total energy is reflected in the bill, for others, the kW-hrs used at peak production. Reducing unnecessary energy is not just for the sake of environmental responsibility, it can lead to huge cost savings.

Energy Units in British Thermal Units (BTUs)

BTUs (British Thermal Units) are the provided energy capacity for gas and liquid fuels. It is quite simple to find values for how many BTUs can be extracted from a gallon of gasoline or diesel, or in a cubic foot of natural gas. However, the efficiency of the system will greatly dictate how much of that energy is actually applied to the load at the end of day.

Related Content: