Calorie, metric unit of heat measurement. The small, or gram, calorie (cal) is usually specified in science and engineering as the amount of heat required to raise the temperature of 1 g of water from 14.5° to 15.5° C. The temperature interval is sometimes specified in other ways. The definition now generally accepted and standard in thermochemistry, is that 1 cal equals 4.1840 joules (J).
A slightly different calorie is used in engineering, the international calorie, which equals 1/860 international watt-hour (W h). A large calorie, or kilocalorie (Cal), usually referred to as a calorie and sometimes as a kilogram calorie, equals 1000 cal and is the unit used to express the energy-producing value of food in the calculation of diets.
A slightly different calorie is used in engineering, the international calorie, which equals 1/860 international watt-hour (W h). A large calorie, or kilocalorie (Cal), usually referred to as a calorie and sometimes as a kilogram calorie, equals 1000 cal and is the unit used to express the energy-producing value of food in the calculation of diets.
