KcalL

kcal/L, or kilocalories per liter, is a unit of energy density used to express the amount of energy contained per liter of a liquid. It is defined as the amount of energy, in kilocalories, stored in one liter of substance. In practice, kcal/L is used primarily in two domains: nutrition and beverages to characterize energy density, and energy or fuel contexts to compare the energy content of liquids such as fuels, oils, and alcohols. The metric is related to the SI unit of energy per volume, the kilojoule per liter (kJ/L), by the conversion 1 kcal/L = 4.184 kJ/L.

Common examples: gasoline has about 8,000 to 8,200 kcal/L, diesel around 8,500 to 9,000 kcal/L, ethanol roughly 6,000 to 6,500 kcal/L, and olive oil about 8,000 to 9,000 kcal/L. In nutrition, liquid foods and fats typically yield several hundred to several thousand kcal per liter, depending on composition; whole milk is around 640 kcal/L, cooking oil around 8,000–9,000 kcal/L.

Kcal/L provides a simple measure of energy density per volume, useful for comparing liquids independently of mass. However, it does not reflect digestibility, metabolic availability, or engine efficiency, which influence usable energy. The unit is not part of the official SI, and energy density is sometimes quoted in kJ/L or kcal/L depending on field conventions. Some datasets may spell the unit as kcalL, though kcal/L is more widely understood.