Therms (UK)
The therm (UK) is a unit of heat energy primarily used in the United Kingdom to measure the energy content of natural gas. It is defined as 100,000 British thermal units (BTUs) which is approximately 105.5 megajoules (MJ).
Calories
A calorie is a unit of energy often used in nutrition to quantify the energy content in food. Specifically, one calorie (cal) is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere.