A unit of heat. One calorie is the amount of heat required to raise the temperature of one gram of water by 1 degree Celsius. One calorie equals 4.180 joules. The older British Thermal Units (BTU) are still in use for some ovens and heating devices. BTU is the amount of heat required to raise the temperature of one pound of water by 1 degree Fahrenheit. One BTU equals 252 calories.
Synonyms and Related Terms
joule; British Thermal Unit; BTU