Therms to Watthours calculator

Therms to Watthours Conversion Table

Below you can generate and download as CSV, Excel, PDF or print the Therms to Watthours conversion table based on your needs.

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• Therm (105,505,600 J)

  Not to be confused with Thermies unit. The therm (symbol, thm) is a non-SI unit of heat energy equal to 100,000 British thermal units (Btu). It is approximately the energy equivalent of burning 100 cubic feet (2.83 cubic metres) – often referred to as 1 CCF – of natural gas. Since natural gas meters measure volume and not energy content, a therm factor is used by natural gas companies to convert the volume of gas used to its heat equivalent, and thus calculate the actual energy use. The therm factor is usually expressed in units of therms per CCF. It will vary with the mix of hydrocarbons in the natural gas. Natural gas with a higher than average concentration of ethane, propane or butane will have a higher therm factor. Impurities, such as carbon dioxide or nitrogen, lower the therm factor. One therm is equal to about 105.5 megajoules, 25200 kilocalories, or 29.3 kilowatt-hours. One therm can also be provided by about 96.7 cubic feet (2.74 m3) of natural gas. The therm sometimes has been confused with the thermie. The names of both units come from the Greek word for heat.

• Watthour (3,600 J)

  The watt hour (symbol Wh) is a unit of energy equal to 3.6 kilojoules. If energy is transmitted or used at a constant rate (power) over a period of time, the total energy in watt hours is equal to the power in watts multiplied by the time in hours. The kilowatt hour is commonly used as a billing unit for energy delivered to consumers by electric utilities.