Conversion unit between calories and joules: 1 calorie = 1 calorie = 4.186 joules; 1 kcal = 1 macrocalorie = 1,000 calories = 1,000 calories = 4,186 joules = 4.186 kilojoules. The unit of conversion between a calorie and a macrocalorie: 1000 calories = 1 macrocalorie.

A calorie (abbreviated "calorie") is defined as the amount of heat required to raise 1 gram of water by 1 degree Celsius at 1 atmosphere. It is still widely used in nutritional measurements and fitness manuals. The international standard unit of energy is the joule (joule).

The macrocalorie, also known as the capital C, is most commonly used in food labeling and is equivalent to the number of calories needed to raise 1,000 grams of water from 14.5 degrees Celsius to 15.5 degrees Celsius at 1 atmosphere, which is equivalent to about 4,186 joules of internal energy. The small calorie, also noted as cal, is more commonly found in scientific research documents, where 1,000 small calories = 1 large calorie.

Expanded Information

Calorie Requirements

Adult Daily Calorie Requirements = Basic calories needed for the body's basal metabolism + calories needed for physical activity + calories needed to digest food.

Calories needed to digest food = 10% x (minimum calories needed for basic metabolism + calories needed for physical activity).

Daily calorie requirement for adults = 1.1 x (minimum essential calories needed for basic metabolism + calories needed for physical activity).

Men: 9250 - 10090 kJ. Women: 7980 - 8820 kJ.

Note: Daily calories provided by food should not be less than 5,000 kilojoules - 7,500 kilojoules, which is the minimum amount of energy needed to maintain normal human life activities.

Baidu Encyclopedia: Calorie