Calories (Kilogram,I.T.)
The kilogram calorie is often referred to as the kilocalorie or Calorie with an uppercase 'C'). It is defined as the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius at one atmosphere of pressure.
Therm (US)
A US therm is 105,480,400 joules, which is 100,000 Btu (59°F) and roughly the energy in 100 cubic feet of natural gas. US gas bills are often given in therms.