therm

therm

Energyexact by definition

The therm is 100,000 International Table BTU, exactly 1.05505585262 × 10⁸ joules, or about 105.5 MJ. It is the billing unit for natural gas in the United States and the United Kingdom, sized so that a therm is roughly what a typical house burns on a cold winter day.

Watch out: Two therms are in circulation. The EC therm used here is 10⁵ BTU_IT. The US therm as defined by NIST uses the 59 °F BTU and comes to 1.054804 × 10⁸ J, a quarter of a percent smaller. Utility billing normally uses the IT figure with a heat content adjustment that swamps the difference anyway. Gas is also sold by the CCF, a hundred cubic feet, which is close to but not equal to a therm because the energy content of gas varies.

1 therm 105,505,590 J