Calories (cal)
The calorie (cal) is defined as exactly 4.184 joules. It quantifies the energy needed to raise the temperature of one gram of water by 1°C under standard conditions. The calorie is widely used in chemistry and nutrition to express energy content [bipm-si-brochure].
Origin
The calorie was introduced in the early 19th century by Nicolas Clément and standardized internationally in the 20th century. It was adopted for practical energy measurement in chemistry and food science before the joule became the SI unit [bipm-si-brochure].
Worldwide Use
Calories remain common in food labeling, nutrition, and chemistry worldwide. The dietary Calorie (kcal) is prevalent in the US, Europe, and many countries while scientific contexts prefer the joule [bipm-si-brochure].
Common References
- Energy content listed on food packaging
- Calorimetry to measure heat in chemical reactions
- Physical exercise energy expenditure calculations
- Nutrition science and diet planning
Calories → Joules1 cal = 4.184 JCalories → Kilojoules1 cal = 0.0042 kJCalories → Megajoules1 cal = 0 MJCalories → Gigajoules1 cal = 0 GJCalories → Kilocalories1 cal = 0.001 kcalCalories → Watt Hours1 cal = 0.0012 WhCalories → Kilowatt Hours1 cal = 0 kWhCalories → Megawatt Hours1 cal = 0 MWhCalories → Electron Volts1 cal = 26,114,473,967,543,833,000 eVCalories → British Thermal Units1 cal = 0.004 BTUCalories → Therms1 cal = 0 thmCalories → Foot-Pounds1 cal = 3.086 ft⋅lbfCalories → Ergs1 cal = 41,840,000 ergCalories → Watts1 cal = 4.184 WCalories → Kilowatts1 cal = 0.0042 kWCalories → Megawatts1 cal = 0 MWCalories → Gigawatts1 cal = 0 GWCalories → Horsepower1 cal = 0.0056 hpCalories → Metric Horsepower1 cal = 0.0057 PSCalories → Foot-Pounds per Minute1 cal = 185.1573 ft⋅lbf/minCalories → Foot-Pounds per Second1 cal = 3.086 ft⋅lbf/sCalories → BTU per Hour1 cal = 14.2764 BTU/hCalories → BTU per Minute1 cal = 0.2379 BTU/minCalories → Tons of Refrigeration1 cal = 0.0012 TRCalories → Milliwatts1 cal = 4,184 mWCalories → Microwatts1 cal = 4,184,000 µWCalories → Nanowatts1 cal = 4,184,000,000 nWCalories → Terawatts1 cal = 0 TWCalories → Petajoules1 cal = 0 PJCalories → Exajoules1 cal = 0 EJCalories → Calories (Nutritional)1 cal = 0.001 CalCalories → Tons of TNT1 cal = 0 tTNTCalories → Kilotons of TNT1 cal = 0 ktTNTCalories → Megatons of TNT1 cal = 0 MtTNTCalories → Barrels of Oil Equivalent1 cal = 0 BOE