Calorie to Kilocalorie Converter

A calorie (cal), also called a small calorie or gram calorie, is a unit of energy equal to approximately 4.184 joules. It represents the energy needed to raise the temperature of one gram of water by one degree Celsius at standard atmospheric pressure.

The calorie was defined by French chemist Nicolas Clément in 1824 as a unit for measuring heat. It was widely used in chemistry and physics for calorimetry and thermodynamics before being largely replaced by the joule in scientific applications, though it remains in use for food energy.

Calories are primarily used in chemistry for small-scale energy measurements, in some scientific literature, and occasionally in food and nutrition contexts. However, they've been largely replaced by joules in scientific applications and by kilocalories (food calories) in nutrition.

A kilocalorie (kcal), also called a food calorie or large calorie, is a unit of energy equal to 1,000 small calories or approximately 4,184 joules. It represents the energy needed to raise the temperature of one kilogram of water by one degree Celsius.

The kilocalorie was developed in the 19th century for measuring heat and energy, particularly in nutrition and metabolism studies. It became the standard unit for food energy content and metabolic energy measurements, though many countries have since adopted kilojoules for food labeling.

Kilocalories are widely used in nutrition and dietetics, particularly in the United States, for measuring food energy content and daily energy requirements. They're found on food labels, diet plans, exercise equipment, and in medical and fitness applications for energy balance calculations.