A therm is a unit of measurement of energy, specifically thermal energy, used to measure gas consumption. One therm is equal to 100,000 British thermal units (BTU), which is approximately 105 megajoules, 29 kilowatt-hours, and 25200 kilocalories. It is the energy content of approximately 100 cubic feet (2.83 cubic meters) of natural gas at standard temperature and pressure. Natural gas meters measure volume and not energy content, so a "therm factor" is used by natural gas companies to convert the volume of gas used to its heat equivalent, usually expressed in units of "therms per CCF" (CCF is an abbreviation for 100 cubic feet) . The heat content of natural gas may vary by location and by type of natural gas consumer, and it may vary over time. Therefore, consumers and analysts should contact natural gas distribution companies or natural gas suppliers for information on the heat content of the natural gas they supply to their customers.